<?xml version="1.0" encoding="us-ascii"?>
<!-- Created by Merrill Corporation -->
<!-- Generated by Fujitsu Interstage XWand B0189 -->
<!--Generated by IRIS XBRL Generation Engine-->
<link:linkbase xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xbrli="http://www.xbrl.org/2003/instance">
  <link:roleRef roleURI="http://www.wfscorp.com/role/DisclosureAcquisitionAndSignificantAccountingPoliciesDetails" xlink:type="simple" xlink:href="int-20140630.xsd#DisclosureAcquisitionAndSignificantAccountingPoliciesDetails" />
  <link:roleRef roleURI="http://www.wfscorp.com/role/DisclosureDebtDetails" xlink:type="simple" xlink:href="int-20140630.xsd#DisclosureDebtDetails" />
  <link:roleRef roleURI="http://www.wfscorp.com/role/CashFlows" xlink:type="simple" xlink:href="int-20140630.xsd#CashFlows" />
  <link:roleRef roleURI="http://www.wfscorp.com/role/BalanceSheet" xlink:type="simple" xlink:href="int-20140630.xsd#BalanceSheet" />
  <link:roleRef roleURI="http://www.wfscorp.com/role/StatementOfIncomeAndComprehensiveIncome" xlink:type="simple" xlink:href="int-20140630.xsd#StatementOfIncomeAndComprehensiveIncome" />
  <link:roleRef roleURI="http://www.wfscorp.com/role/StatementOfIncomeAndComprehensiveIncomeCalc2" xlink:type="simple" xlink:href="int-20140630.xsd#StatementOfIncomeAndComprehensiveIncomeCalc2" />
  <link:roleRef roleURI="http://www.wfscorp.com/role/DisclosureEarningsPerCommonShareDetails" xlink:type="simple" xlink:href="int-20140630.xsd#DisclosureEarningsPerCommonShareDetails" />
  <link:calculationLink xlink:type="extended" xlink:role="http://www.wfscorp.com/role/DisclosureAcquisitionAndSignificantAccountingPoliciesDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesGross" xlink:label="PaymentsToAcquireBusinessesGross" xlink:title="PaymentsToAcquireBusinessesGross" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:label="PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:title="PaymentsToAcquireBusinessesNetOfCashAcquired" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="PaymentsToAcquireBusinessesGross" xlink:to="PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:title="calculation: PaymentsToAcquireBusinessesGross to PaymentsToAcquireBusinessesNetOfCashAcquired" use="optional" order="1.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:label="BusinessCombinationConsiderationTransferred1" xlink:title="BusinessCombinationConsiderationTransferred1" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:to="BusinessCombinationConsiderationTransferred1" xlink:title="calculation: PaymentsToAcquireBusinessesNetOfCashAcquired to BusinessCombinationConsiderationTransferred1" use="optional" order="1.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CashAcquiredFromAcquisition" xlink:label="CashAcquiredFromAcquisition" xlink:title="CashAcquiredFromAcquisition" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:to="CashAcquiredFromAcquisition" xlink:title="calculation: PaymentsToAcquireBusinessesNetOfCashAcquired to CashAcquiredFromAcquisition" use="optional" order="2.0" weight="-1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferredLiabilitiesIncurred" xlink:label="BusinessCombinationConsiderationTransferredLiabilitiesIncurred" xlink:title="BusinessCombinationConsiderationTransferredLiabilitiesIncurred" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="PaymentsToAcquireBusinessesGross" xlink:to="BusinessCombinationConsiderationTransferredLiabilitiesIncurred" xlink:title="calculation: PaymentsToAcquireBusinessesGross to BusinessCombinationConsiderationTransferredLiabilitiesIncurred" use="optional" order="2.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest" xlink:label="BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" xlink:label="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest" xlink:to="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" xlink:title="calculation: BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest to BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" use="optional" order="1.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:label="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest" xlink:to="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:title="calculation: BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest to BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" use="optional" order="2.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory" xlink:label="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest" xlink:to="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory" xlink:title="calculation: BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest to BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory" use="optional" order="3.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" xlink:label="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest" xlink:to="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" xlink:title="calculation: BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest to BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" use="optional" order="4.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill" xlink:label="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest" xlink:to="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill" xlink:title="calculation: BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest to BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill" use="optional" order="5.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_Goodwill" xlink:label="Goodwill" xlink:title="Goodwill" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest" xlink:to="Goodwill" xlink:title="calculation: BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest to Goodwill" use="optional" order="6.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="int-20140630.xsd#int_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherCurrentAndLongTermAssets" xlink:label="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherCurrentAndLongTermAssets" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherCurrentAndLongTermAssets" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest" xlink:to="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherCurrentAndLongTermAssets" xlink:title="calculation: BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest to BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherCurrentAndLongTermAssets" use="optional" order="7.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable" xlink:label="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest" xlink:to="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable" xlink:title="calculation: BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest to BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable" use="optional" order="8.0" weight="-1" />
    <link:loc xlink:type="locator" xlink:href="int-20140630.xsd#int_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccruedExpenseAndOtherCurrentLiabilities" xlink:label="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccruedExpenseAndOtherCurrentLiabilities" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccruedExpenseAndOtherCurrentLiabilities" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest" xlink:to="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccruedExpenseAndOtherCurrentLiabilities" xlink:title="calculation: BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest to BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccruedExpenseAndOtherCurrentLiabilities" use="optional" order="9.0" weight="-1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther" xlink:label="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest" xlink:to="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther" xlink:title="calculation: BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest to BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther" use="optional" order="10.0" weight="-1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationAcquisitionOfLessThan100PercentNoncontrollingInterestFairValue" xlink:label="BusinessCombinationAcquisitionOfLessThan100PercentNoncontrollingInterestFairValue" xlink:title="BusinessCombinationAcquisitionOfLessThan100PercentNoncontrollingInterestFairValue" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest" xlink:to="BusinessCombinationAcquisitionOfLessThan100PercentNoncontrollingInterestFairValue" xlink:title="calculation: BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest to BusinessCombinationAcquisitionOfLessThan100PercentNoncontrollingInterestFairValue" use="optional" order="11.0" weight="-1" />
  </link:calculationLink>
  <link:calculationLink xlink:type="extended" xlink:role="http://www.wfscorp.com/role/DisclosureDebtDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtAndCapitalLeaseObligations" xlink:label="DebtAndCapitalLeaseObligations" xlink:title="DebtAndCapitalLeaseObligations" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShortTermBorrowings" xlink:label="ShortTermBorrowings" xlink:title="ShortTermBorrowings" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DebtAndCapitalLeaseObligations" xlink:to="ShortTermBorrowings" xlink:title="calculation: DebtAndCapitalLeaseObligations to ShortTermBorrowings" use="optional" order="1.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligations" xlink:label="LongTermDebtAndCapitalLeaseObligations" xlink:title="LongTermDebtAndCapitalLeaseObligations" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DebtAndCapitalLeaseObligations" xlink:to="LongTermDebtAndCapitalLeaseObligations" xlink:title="calculation: DebtAndCapitalLeaseObligations to LongTermDebtAndCapitalLeaseObligations" use="optional" order="2.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="int-20140630.xsd#int_InterestIncomeExpenseAndOtherFinancialCostsNet" xlink:label="InterestIncomeExpenseAndOtherFinancialCostsNet" xlink:title="InterestIncomeExpenseAndOtherFinancialCostsNet" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestIncomeOther" xlink:label="InterestIncomeOther" xlink:title="InterestIncomeOther" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="InterestIncomeExpenseAndOtherFinancialCostsNet" xlink:to="InterestIncomeOther" xlink:title="calculation: InterestIncomeExpenseAndOtherFinancialCostsNet to InterestIncomeOther" use="optional" order="1.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestExpense" xlink:label="InterestExpense" xlink:title="InterestExpense" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="InterestIncomeExpenseAndOtherFinancialCostsNet" xlink:to="InterestExpense" xlink:title="calculation: InterestIncomeExpenseAndOtherFinancialCostsNet to InterestExpense" use="optional" order="2.0" weight="-1" />
  </link:calculationLink>
  <link:calculationLink xlink:type="extended" xlink:role="http://www.wfscorp.com/role/CashFlows">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NetCashProvidedByUsedInContinuingOperations" xlink:label="NetCashProvidedByUsedInContinuingOperations" xlink:title="NetCashProvidedByUsedInContinuingOperations" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" xlink:label="NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" xlink:title="NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInContinuingOperations" xlink:to="NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" xlink:title="calculation: NetCashProvidedByUsedInContinuingOperations to NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" use="optional" order="1.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProfitLoss" xlink:label="ProfitLoss" xlink:title="ProfitLoss" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" xlink:to="ProfitLoss" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivitiesContinuingOperations to ProfitLoss" use="optional" order="1.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:label="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:title="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" xlink:to="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivitiesContinuingOperations to AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" use="optional" order="2.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DepreciationAndAmortization" xlink:label="DepreciationAndAmortization" xlink:title="DepreciationAndAmortization" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:to="DepreciationAndAmortization" xlink:title="calculation: AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities to DepreciationAndAmortization" use="optional" order="1.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProvisionForDoubtfulAccounts" xlink:label="ProvisionForDoubtfulAccounts" xlink:title="ProvisionForDoubtfulAccounts" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:to="ProvisionForDoubtfulAccounts" xlink:title="calculation: AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities to ProvisionForDoubtfulAccounts" use="optional" order="2.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensation" xlink:label="ShareBasedCompensation" xlink:title="ShareBasedCompensation" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:to="ShareBasedCompensation" xlink:title="calculation: AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities to ShareBasedCompensation" use="optional" order="3.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:label="DeferredIncomeTaxExpenseBenefit" xlink:title="DeferredIncomeTaxExpenseBenefit" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:to="DeferredIncomeTaxExpenseBenefit" xlink:title="calculation: AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities to DeferredIncomeTaxExpenseBenefit" use="optional" order="4.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:label="GainsLossesOnExtinguishmentOfDebt" xlink:title="GainsLossesOnExtinguishmentOfDebt" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:to="GainsLossesOnExtinguishmentOfDebt" xlink:title="calculation: AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities to GainsLossesOnExtinguishmentOfDebt" use="optional" order="5.0" weight="-1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherNoncashIncomeExpense" xlink:label="OtherNoncashIncomeExpense" xlink:title="OtherNoncashIncomeExpense" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:to="OtherNoncashIncomeExpense" xlink:title="calculation: AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities to OtherNoncashIncomeExpense" use="optional" order="6.0" weight="-1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:label="IncreaseDecreaseInAccountsReceivable" xlink:title="IncreaseDecreaseInAccountsReceivable" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:to="IncreaseDecreaseInAccountsReceivable" xlink:title="calculation: AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities to IncreaseDecreaseInAccountsReceivable" use="optional" order="7.0" weight="-1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncreaseDecreaseInInventories" xlink:label="IncreaseDecreaseInInventories" xlink:title="IncreaseDecreaseInInventories" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:to="IncreaseDecreaseInInventories" xlink:title="calculation: AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities to IncreaseDecreaseInInventories" use="optional" order="8.0" weight="-1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncreaseDecreaseInPrepaidExpense" xlink:label="IncreaseDecreaseInPrepaidExpense" xlink:title="IncreaseDecreaseInPrepaidExpense" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:to="IncreaseDecreaseInPrepaidExpense" xlink:title="calculation: AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities to IncreaseDecreaseInPrepaidExpense" use="optional" order="9.0" weight="-1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:label="IncreaseDecreaseInOtherOperatingAssets" xlink:title="IncreaseDecreaseInOtherOperatingAssets" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:to="IncreaseDecreaseInOtherOperatingAssets" xlink:title="calculation: AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities to IncreaseDecreaseInOtherOperatingAssets" use="optional" order="10.0" weight="-1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncreaseDecreaseCashCollateralFromCounterparties" xlink:label="IncreaseDecreaseCashCollateralFromCounterparties" xlink:title="IncreaseDecreaseCashCollateralFromCounterparties" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:to="IncreaseDecreaseCashCollateralFromCounterparties" xlink:title="calculation: AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities to IncreaseDecreaseCashCollateralFromCounterparties" use="optional" order="11.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncreaseDecreaseInOtherNoncurrentAssets" xlink:label="IncreaseDecreaseInOtherNoncurrentAssets" xlink:title="IncreaseDecreaseInOtherNoncurrentAssets" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:to="IncreaseDecreaseInOtherNoncurrentAssets" xlink:title="calculation: AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities to IncreaseDecreaseInOtherNoncurrentAssets" use="optional" order="12.0" weight="-1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsPayable" xlink:label="IncreaseDecreaseInAccountsPayable" xlink:title="IncreaseDecreaseInAccountsPayable" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:to="IncreaseDecreaseInAccountsPayable" xlink:title="calculation: AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities to IncreaseDecreaseInAccountsPayable" use="optional" order="13.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncreaseDecreaseInCustomerDeposits" xlink:label="IncreaseDecreaseInCustomerDeposits" xlink:title="IncreaseDecreaseInCustomerDeposits" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:to="IncreaseDecreaseInCustomerDeposits" xlink:title="calculation: AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities to IncreaseDecreaseInCustomerDeposits" use="optional" order="14.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="int-20140630.xsd#int_IncreaseDecreaseInAccruedExpensesAndOtherLiabilities" xlink:label="IncreaseDecreaseInAccruedExpensesAndOtherLiabilities" xlink:title="IncreaseDecreaseInAccruedExpensesAndOtherLiabilities" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:to="IncreaseDecreaseInAccruedExpensesAndOtherLiabilities" xlink:title="calculation: AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities to IncreaseDecreaseInAccruedExpensesAndOtherLiabilities" use="optional" order="15.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="int-20140630.xsd#int_IncreaseDecreaseInIncomeTaxAndOtherLiabilitiesNoncurrent" xlink:label="IncreaseDecreaseInIncomeTaxAndOtherLiabilitiesNoncurrent" xlink:title="IncreaseDecreaseInIncomeTaxAndOtherLiabilitiesNoncurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:to="IncreaseDecreaseInIncomeTaxAndOtherLiabilitiesNoncurrent" xlink:title="calculation: AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities to IncreaseDecreaseInIncomeTaxAndOtherLiabilitiesNoncurrent" use="optional" order="16.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" xlink:label="NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" xlink:title="NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInContinuingOperations" xlink:to="NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" xlink:title="calculation: NetCashProvidedByUsedInContinuingOperations to NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" use="optional" order="2.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:label="PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:title="PaymentsToAcquireBusinessesNetOfCashAcquired" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" xlink:to="PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:title="calculation: NetCashProvidedByUsedInInvestingActivitiesContinuingOperations to PaymentsToAcquireBusinessesNetOfCashAcquired" use="optional" order="1.0" weight="-1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:label="PaymentsToAcquirePropertyPlantAndEquipment" xlink:title="PaymentsToAcquirePropertyPlantAndEquipment" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" xlink:to="PaymentsToAcquirePropertyPlantAndEquipment" xlink:title="calculation: NetCashProvidedByUsedInInvestingActivitiesContinuingOperations to PaymentsToAcquirePropertyPlantAndEquipment" use="optional" order="2.0" weight="-1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncreaseDecreaseInRestrictedCash" xlink:label="IncreaseDecreaseInRestrictedCash" xlink:title="IncreaseDecreaseInRestrictedCash" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" xlink:to="IncreaseDecreaseInRestrictedCash" xlink:title="calculation: NetCashProvidedByUsedInInvestingActivitiesContinuingOperations to IncreaseDecreaseInRestrictedCash" use="optional" order="3.0" weight="-1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PaymentsToAcquireInvestments" xlink:label="PaymentsToAcquireInvestments" xlink:title="PaymentsToAcquireInvestments" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" xlink:to="PaymentsToAcquireInvestments" xlink:title="calculation: NetCashProvidedByUsedInInvestingActivitiesContinuingOperations to PaymentsToAcquireInvestments" use="optional" order="4.0" weight="-1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromSaleOfShortTermInvestments" xlink:label="ProceedsFromSaleOfShortTermInvestments" xlink:title="ProceedsFromSaleOfShortTermInvestments" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" xlink:to="ProceedsFromSaleOfShortTermInvestments" xlink:title="calculation: NetCashProvidedByUsedInInvestingActivitiesContinuingOperations to ProceedsFromSaleOfShortTermInvestments" use="optional" order="5.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromCollectionOfNotesReceivable" xlink:label="ProceedsFromCollectionOfNotesReceivable" xlink:title="ProceedsFromCollectionOfNotesReceivable" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" xlink:to="ProceedsFromCollectionOfNotesReceivable" xlink:title="calculation: NetCashProvidedByUsedInInvestingActivitiesContinuingOperations to ProceedsFromCollectionOfNotesReceivable" use="optional" order="6.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:label="NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:title="NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInContinuingOperations" xlink:to="NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:title="calculation: NetCashProvidedByUsedInContinuingOperations to NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" use="optional" order="3.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromLinesOfCredit" xlink:label="ProceedsFromLinesOfCredit" xlink:title="ProceedsFromLinesOfCredit" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:to="ProceedsFromLinesOfCredit" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivitiesContinuingOperations to ProceedsFromLinesOfCredit" use="optional" order="1.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RepaymentsOfLinesOfCredit" xlink:label="RepaymentsOfLinesOfCredit" xlink:title="RepaymentsOfLinesOfCredit" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:to="RepaymentsOfLinesOfCredit" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivitiesContinuingOperations to RepaymentsOfLinesOfCredit" use="optional" order="2.0" weight="-1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromOtherDebt" xlink:label="ProceedsFromOtherDebt" xlink:title="ProceedsFromOtherDebt" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:to="ProceedsFromOtherDebt" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivitiesContinuingOperations to ProceedsFromOtherDebt" use="optional" order="3.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RepaymentsOfOtherDebt" xlink:label="RepaymentsOfOtherDebt" xlink:title="RepaymentsOfOtherDebt" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:to="RepaymentsOfOtherDebt" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivitiesContinuingOperations to RepaymentsOfOtherDebt" use="optional" order="4.0" weight="-1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PaymentsOfDividendsCommonStock" xlink:label="PaymentsOfDividendsCommonStock" xlink:title="PaymentsOfDividendsCommonStock" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:to="PaymentsOfDividendsCommonStock" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivitiesContinuingOperations to PaymentsOfDividendsCommonStock" use="optional" order="5.0" weight="-1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PaymentsOfDividendsMinorityInterest" xlink:label="PaymentsOfDividendsMinorityInterest" xlink:title="PaymentsOfDividendsMinorityInterest" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:to="PaymentsOfDividendsMinorityInterest" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivitiesContinuingOperations to PaymentsOfDividendsMinorityInterest" use="optional" order="6.0" weight="-1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities" xlink:label="ExcessTaxBenefitFromShareBasedCompensationFinancingActivities" xlink:title="ExcessTaxBenefitFromShareBasedCompensationFinancingActivities" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:to="ExcessTaxBenefitFromShareBasedCompensationFinancingActivities" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivitiesContinuingOperations to ExcessTaxBenefitFromShareBasedCompensationFinancingActivities" use="optional" order="7.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="int-20140630.xsd#int_PaymentsForRepurchaseOfCommonStockToSatisfyEmployeeTaxWithholdingObligations" xlink:label="PaymentsForRepurchaseOfCommonStockToSatisfyEmployeeTaxWithholdingObligations" xlink:title="PaymentsForRepurchaseOfCommonStockToSatisfyEmployeeTaxWithholdingObligations" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:to="PaymentsForRepurchaseOfCommonStockToSatisfyEmployeeTaxWithholdingObligations" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivitiesContinuingOperations to PaymentsForRepurchaseOfCommonStockToSatisfyEmployeeTaxWithholdingObligations" use="optional" order="8.0" weight="-1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EffectOfExchangeRateOnCashAndCashEquivalentsContinuingOperations" xlink:label="EffectOfExchangeRateOnCashAndCashEquivalentsContinuingOperations" xlink:title="EffectOfExchangeRateOnCashAndCashEquivalentsContinuingOperations" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInContinuingOperations" xlink:to="EffectOfExchangeRateOnCashAndCashEquivalentsContinuingOperations" xlink:title="calculation: NetCashProvidedByUsedInContinuingOperations to EffectOfExchangeRateOnCashAndCashEquivalentsContinuingOperations" use="optional" order="4.0" weight="1" />
  </link:calculationLink>
  <link:calculationLink xlink:type="extended" xlink:role="http://www.wfscorp.com/role/BalanceSheet">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_Assets" xlink:label="Assets" xlink:title="Assets" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AssetsCurrent" xlink:label="AssetsCurrent" xlink:title="AssetsCurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Assets" xlink:to="AssetsCurrent" xlink:title="calculation: Assets to AssetsCurrent" order="1.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="CashAndCashEquivalentsAtCarryingValue" xlink:title="CashAndCashEquivalentsAtCarryingValue" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AssetsCurrent" xlink:to="CashAndCashEquivalentsAtCarryingValue" xlink:title="calculation: AssetsCurrent to CashAndCashEquivalentsAtCarryingValue" use="optional" order="1.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:label="AccountsReceivableNetCurrent" xlink:title="AccountsReceivableNetCurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AssetsCurrent" xlink:to="AccountsReceivableNetCurrent" xlink:title="calculation: AssetsCurrent to AccountsReceivableNetCurrent" use="optional" order="2.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InventoryNet" xlink:label="InventoryNet" xlink:title="InventoryNet" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AssetsCurrent" xlink:to="InventoryNet" xlink:title="calculation: AssetsCurrent to InventoryNet" use="optional" order="3.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PrepaidExpenseCurrent" xlink:label="PrepaidExpenseCurrent" xlink:title="PrepaidExpenseCurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AssetsCurrent" xlink:to="PrepaidExpenseCurrent" xlink:title="calculation: AssetsCurrent to PrepaidExpenseCurrent" use="optional" order="4.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherAssetsCurrent" xlink:label="OtherAssetsCurrent" xlink:title="OtherAssetsCurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AssetsCurrent" xlink:to="OtherAssetsCurrent" xlink:title="calculation: AssetsCurrent to OtherAssetsCurrent" use="optional" order="5.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="PropertyPlantAndEquipmentNet" xlink:title="PropertyPlantAndEquipmentNet" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Assets" xlink:to="PropertyPlantAndEquipmentNet" xlink:title="calculation: Assets to PropertyPlantAndEquipmentNet" use="optional" order="2.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_Goodwill" xlink:label="Goodwill" xlink:title="Goodwill" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Assets" xlink:to="Goodwill" xlink:title="calculation: Assets to Goodwill" use="optional" order="3.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="int-20140630.xsd#int_IntangibleAssetsNetExcludingGoodwillAndOtherAssetsNoncurrent" xlink:label="IntangibleAssetsNetExcludingGoodwillAndOtherAssetsNoncurrent" xlink:title="IntangibleAssetsNetExcludingGoodwillAndOtherAssetsNoncurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Assets" xlink:to="IntangibleAssetsNetExcludingGoodwillAndOtherAssetsNoncurrent" xlink:title="calculation: Assets to IntangibleAssetsNetExcludingGoodwillAndOtherAssetsNoncurrent" use="optional" order="4.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="LiabilitiesAndStockholdersEquity" xlink:title="LiabilitiesAndStockholdersEquity" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_Liabilities" xlink:label="Liabilities" xlink:title="Liabilities" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LiabilitiesAndStockholdersEquity" xlink:to="Liabilities" xlink:title="calculation: LiabilitiesAndStockholdersEquity to Liabilities" order="1.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:label="LiabilitiesCurrent" xlink:title="LiabilitiesCurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Liabilities" xlink:to="LiabilitiesCurrent" xlink:title="calculation: Liabilities to LiabilitiesCurrent" use="optional" order="1.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtCurrent" xlink:label="DebtCurrent" xlink:title="DebtCurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LiabilitiesCurrent" xlink:to="DebtCurrent" xlink:title="calculation: LiabilitiesCurrent to DebtCurrent" use="optional" order="1.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccountsPayableCurrent" xlink:label="AccountsPayableCurrent" xlink:title="AccountsPayableCurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LiabilitiesCurrent" xlink:to="AccountsPayableCurrent" xlink:title="calculation: LiabilitiesCurrent to AccountsPayableCurrent" use="optional" order="2.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CustomerDepositsCurrent" xlink:label="CustomerDepositsCurrent" xlink:title="CustomerDepositsCurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LiabilitiesCurrent" xlink:to="CustomerDepositsCurrent" xlink:title="calculation: LiabilitiesCurrent to CustomerDepositsCurrent" use="optional" order="3.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:label="AccruedLiabilitiesCurrent" xlink:title="AccruedLiabilitiesCurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LiabilitiesCurrent" xlink:to="AccruedLiabilitiesCurrent" xlink:title="calculation: LiabilitiesCurrent to AccruedLiabilitiesCurrent" use="optional" order="4.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligations" xlink:label="LongTermDebtAndCapitalLeaseObligations" xlink:title="LongTermDebtAndCapitalLeaseObligations" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Liabilities" xlink:to="LongTermDebtAndCapitalLeaseObligations" xlink:title="calculation: Liabilities to LongTermDebtAndCapitalLeaseObligations" order="2.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccruedIncomeTaxesNoncurrent" xlink:label="AccruedIncomeTaxesNoncurrent" xlink:title="AccruedIncomeTaxesNoncurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Liabilities" xlink:to="AccruedIncomeTaxesNoncurrent" xlink:title="calculation: Liabilities to AccruedIncomeTaxesNoncurrent" use="optional" order="3.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="int-20140630.xsd#int_DeferredCompensationLiabilityClassifiedAndOtherLiabilitiesNoncurrent" xlink:label="DeferredCompensationLiabilityClassifiedAndOtherLiabilitiesNoncurrent" xlink:title="DeferredCompensationLiabilityClassifiedAndOtherLiabilitiesNoncurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Liabilities" xlink:to="DeferredCompensationLiabilityClassifiedAndOtherLiabilitiesNoncurrent" xlink:title="calculation: Liabilities to DeferredCompensationLiabilityClassifiedAndOtherLiabilitiesNoncurrent" use="optional" order="4.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:label="StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:title="StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LiabilitiesAndStockholdersEquity" xlink:to="StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:title="calculation: LiabilitiesAndStockholdersEquity to StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" order="2.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="StockholdersEquity" xlink:title="StockholdersEquity" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:to="StockholdersEquity" xlink:title="calculation: StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest to StockholdersEquity" order="1.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockValue" xlink:label="PreferredStockValue" xlink:title="PreferredStockValue" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquity" xlink:to="PreferredStockValue" xlink:title="calculation: StockholdersEquity to PreferredStockValue" use="optional" order="1.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockValue" xlink:label="CommonStockValue" xlink:title="CommonStockValue" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquity" xlink:to="CommonStockValue" xlink:title="calculation: StockholdersEquity to CommonStockValue" use="optional" order="2.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdditionalPaidInCapitalCommonStock" xlink:label="AdditionalPaidInCapitalCommonStock" xlink:title="AdditionalPaidInCapitalCommonStock" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquity" xlink:to="AdditionalPaidInCapitalCommonStock" xlink:title="calculation: StockholdersEquity to AdditionalPaidInCapitalCommonStock" use="optional" order="3.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="RetainedEarningsAccumulatedDeficit" xlink:title="RetainedEarningsAccumulatedDeficit" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquity" xlink:to="RetainedEarningsAccumulatedDeficit" xlink:title="calculation: StockholdersEquity to RetainedEarningsAccumulatedDeficit" use="optional" order="4.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:title="AccumulatedOtherComprehensiveIncomeLossNetOfTax" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquity" xlink:to="AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:title="calculation: StockholdersEquity to AccumulatedOtherComprehensiveIncomeLossNetOfTax" use="optional" order="5.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MinorityInterest" xlink:label="MinorityInterest" xlink:title="MinorityInterest" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:to="MinorityInterest" xlink:title="calculation: StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest to MinorityInterest" order="2.0" weight="1" />
  </link:calculationLink>
  <link:calculationLink xlink:type="extended" xlink:role="http://www.wfscorp.com/role/StatementOfIncomeAndComprehensiveIncome">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProfitLoss" xlink:label="ProfitLoss" xlink:title="ProfitLoss" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:label="IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:title="IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="ProfitLoss" xlink:to="IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:title="calculation: ProfitLoss to IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" use="optional" order="1.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="OperatingIncomeLoss" xlink:title="OperatingIncomeLoss" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:to="OperatingIncomeLoss" xlink:title="calculation: IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments to OperatingIncomeLoss" use="optional" order="1.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_GrossProfit" xlink:label="GrossProfit" xlink:title="GrossProfit" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingIncomeLoss" xlink:to="GrossProfit" xlink:title="calculation: OperatingIncomeLoss to GrossProfit" use="optional" order="1.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_Revenues" xlink:label="Revenues" xlink:title="Revenues" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="GrossProfit" xlink:to="Revenues" xlink:title="calculation: GrossProfit to Revenues" use="optional" order="1.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CostOfRevenue" xlink:label="CostOfRevenue" xlink:title="CostOfRevenue" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="GrossProfit" xlink:to="CostOfRevenue" xlink:title="calculation: GrossProfit to CostOfRevenue" use="optional" order="2.0" weight="-1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingExpenses" xlink:label="OperatingExpenses" xlink:title="OperatingExpenses" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingIncomeLoss" xlink:to="OperatingExpenses" xlink:title="calculation: OperatingIncomeLoss to OperatingExpenses" use="optional" order="2.0" weight="-1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LaborAndRelatedExpense" xlink:label="LaborAndRelatedExpense" xlink:title="LaborAndRelatedExpense" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingExpenses" xlink:to="LaborAndRelatedExpense" xlink:title="calculation: OperatingExpenses to LaborAndRelatedExpense" use="optional" order="1.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProvisionForDoubtfulAccounts" xlink:label="ProvisionForDoubtfulAccounts" xlink:title="ProvisionForDoubtfulAccounts" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingExpenses" xlink:to="ProvisionForDoubtfulAccounts" xlink:title="calculation: OperatingExpenses to ProvisionForDoubtfulAccounts" use="optional" order="2.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_GeneralAndAdministrativeExpense" xlink:label="GeneralAndAdministrativeExpense" xlink:title="GeneralAndAdministrativeExpense" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingExpenses" xlink:to="GeneralAndAdministrativeExpense" xlink:title="calculation: OperatingExpenses to GeneralAndAdministrativeExpense" use="optional" order="3.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NonoperatingIncomeExpense" xlink:label="NonoperatingIncomeExpense" xlink:title="NonoperatingIncomeExpense" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:to="NonoperatingIncomeExpense" xlink:title="calculation: IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments to NonoperatingIncomeExpense" use="optional" order="2.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="int-20140630.xsd#int_InterestIncomeExpenseAndOtherFinancialCostsNet" xlink:label="InterestIncomeExpenseAndOtherFinancialCostsNet" xlink:title="InterestIncomeExpenseAndOtherFinancialCostsNet" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NonoperatingIncomeExpense" xlink:to="InterestIncomeExpenseAndOtherFinancialCostsNet" xlink:title="calculation: NonoperatingIncomeExpense to InterestIncomeExpenseAndOtherFinancialCostsNet" use="optional" order="1.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="OtherNonoperatingIncomeExpense" xlink:title="OtherNonoperatingIncomeExpense" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NonoperatingIncomeExpense" xlink:to="OtherNonoperatingIncomeExpense" xlink:title="calculation: NonoperatingIncomeExpense to OtherNonoperatingIncomeExpense" use="optional" order="2.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="IncomeTaxExpenseBenefit" xlink:title="IncomeTaxExpenseBenefit" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="ProfitLoss" xlink:to="IncomeTaxExpenseBenefit" xlink:title="calculation: ProfitLoss to IncomeTaxExpenseBenefit" use="optional" order="2.0" weight="-1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:label="NetIncomeLossAvailableToCommonStockholdersBasic" xlink:title="NetIncomeLossAvailableToCommonStockholdersBasic" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetIncomeLossAvailableToCommonStockholdersBasic" xlink:to="ProfitLoss" xlink:title="calculation: NetIncomeLossAvailableToCommonStockholdersBasic to ProfitLoss" use="optional" order="1.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest" xlink:label="NetIncomeLossAttributableToNoncontrollingInterest" xlink:title="NetIncomeLossAttributableToNoncontrollingInterest" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetIncomeLossAvailableToCommonStockholdersBasic" xlink:to="NetIncomeLossAttributableToNoncontrollingInterest" xlink:title="calculation: NetIncomeLossAvailableToCommonStockholdersBasic to NetIncomeLossAttributableToNoncontrollingInterest" use="optional" order="2.0" weight="-1" />
  </link:calculationLink>
  <link:calculationLink xlink:type="extended" xlink:role="http://www.wfscorp.com/role/StatementOfIncomeAndComprehensiveIncomeCalc2">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTax" xlink:label="ComprehensiveIncomeNetOfTax" xlink:title="ComprehensiveIncomeNetOfTax" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest" xlink:label="ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest" xlink:title="ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="ComprehensiveIncomeNetOfTax" xlink:to="ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest" xlink:title="calculation: ComprehensiveIncomeNetOfTax to ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest" use="optional" order="1.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProfitLoss" xlink:label="ProfitLoss" xlink:title="ProfitLoss" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest" xlink:to="ProfitLoss" xlink:title="calculation: ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest to ProfitLoss" use="optional" order="1.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:label="OtherComprehensiveIncomeLossNetOfTax" xlink:title="OtherComprehensiveIncomeLossNetOfTax" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest" xlink:to="OtherComprehensiveIncomeLossNetOfTax" xlink:title="calculation: ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest to OtherComprehensiveIncomeLossNetOfTax" use="optional" order="2.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax" xlink:label="OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax" xlink:title="OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OtherComprehensiveIncomeLossNetOfTax" xlink:to="OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax" xlink:title="calculation: OtherComprehensiveIncomeLossNetOfTax to OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax" use="optional" order="1.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" xlink:label="OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" xlink:title="OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OtherComprehensiveIncomeLossNetOfTax" xlink:to="OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" xlink:title="calculation: OtherComprehensiveIncomeLossNetOfTax to OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" use="optional" order="2.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest" xlink:label="ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest" xlink:title="ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="ComprehensiveIncomeNetOfTax" xlink:to="ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest" xlink:title="calculation: ComprehensiveIncomeNetOfTax to ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest" use="optional" order="2.0" weight="-1" />
  </link:calculationLink>
  <link:calculationLink xlink:type="extended" xlink:role="http://www.wfscorp.com/role/DisclosureEarningsPerCommonShareDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:label="WeightedAverageNumberOfDilutedSharesOutstanding" xlink:title="WeightedAverageNumberOfDilutedSharesOutstanding" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:label="WeightedAverageNumberOfSharesOutstandingBasic" xlink:title="WeightedAverageNumberOfSharesOutstandingBasic" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="WeightedAverageNumberOfDilutedSharesOutstanding" xlink:to="WeightedAverageNumberOfSharesOutstandingBasic" xlink:title="calculation: WeightedAverageNumberOfDilutedSharesOutstanding to WeightedAverageNumberOfSharesOutstandingBasic" use="optional" order="1.0" weight="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment" xlink:label="WeightedAverageNumberDilutedSharesOutstandingAdjustment" xlink:title="WeightedAverageNumberDilutedSharesOutstandingAdjustment" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="WeightedAverageNumberOfDilutedSharesOutstanding" xlink:to="WeightedAverageNumberDilutedSharesOutstandingAdjustment" xlink:title="calculation: WeightedAverageNumberOfDilutedSharesOutstanding to WeightedAverageNumberDilutedSharesOutstandingAdjustment" use="optional" order="2.0" weight="1" />
  </link:calculationLink>
</link:linkbase>
