<?xml version="1.0" encoding="utf-8"?>
<Return xmlns="http://www.irs.gov/efile" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" returnVersion="2021v4.0">
  <ReturnHeader binaryAttachmentCnt="0">
    <ReturnTs>2022-08-15T15:59:10-05:00</ReturnTs>
    <TaxPeriodEndDt>2021-12-31</TaxPeriodEndDt>
    <PreparerFirmGrp>
      <PreparerFirmEIN>141716227</PreparerFirmEIN>
      <PreparerFirmName>
        <BusinessNameLine1Txt>RANK &amp; SMITH CPA</BusinessNameLine1Txt>
      </PreparerFirmName>
      <PreparerUSAddress>
        <AddressLine1Txt>243 HUDSON ST</AddressLine1Txt>
        <CityNm>CORNWALL ON HUDSON</CityNm>
        <StateAbbreviationCd>NY</StateAbbreviationCd>
        <ZIPCd>125201520</ZIPCd>
      </PreparerUSAddress>
    </PreparerFirmGrp>
    <ReturnTypeCd>990EZ</ReturnTypeCd>
    <TaxPeriodBeginDt>2021-01-01</TaxPeriodBeginDt>
    <Filer>
      <EIN>813381857</EIN>
      <BusinessName>
        <BusinessNameLine1Txt>SIMIODE</BusinessNameLine1Txt>
      </BusinessName>
      <BusinessNameControlTxt>SIMI</BusinessNameControlTxt>
      <PhoneNum>8455687119</PhoneNum>
      <USAddress>
        <AddressLine1Txt>10460 LOCUST GROVE DR</AddressLine1Txt>
        <CityNm>CHARDON</CityNm>
        <StateAbbreviationCd>OH</StateAbbreviationCd>
        <ZIPCd>44024</ZIPCd>
      </USAddress>
    </Filer>
    <BusinessOfficerGrp>
      <PersonNm>BRIAN J WINKEL</PersonNm>
      <PersonTitleTxt>DIRECTOR</PersonTitleTxt>
      <PhoneNum>8455687119</PhoneNum>
      <SignatureDt>2022-08-15</SignatureDt>
      <DiscussWithPaidPreparerInd>true</DiscussWithPaidPreparerInd>
    </BusinessOfficerGrp>
    <SigningOfficerGrp>
      <PersonFullName>
        <PersonFirstNm>BRIAN</PersonFirstNm>
        <PersonLastNm>WINKEL</PersonLastNm>
      </PersonFullName>
      <SSN>XXX-XX-XXXX</SSN>
    </SigningOfficerGrp>
    <PreparerPersonGrp>
      <PreparerPersonNm>GARY L RANK</PreparerPersonNm>
      <PTIN>P00045429</PTIN>
      <PhoneNum>8455342300</PhoneNum>
      <PreparationDt>2022-08-15</PreparationDt>
    </PreparerPersonGrp>
    <TaxYr>2021</TaxYr>
    <BuildTS>2022-09-23 18:48:47Z</BuildTS>
  </ReturnHeader>
  <ReturnData documentCnt="3">
    <IRS990EZ documentId="RetDoc1" referenceDocumentId="RetDoc2">
      <MethodOfAccountingCashInd>X</MethodOfAccountingCashInd>
      <ScheduleBNotRequiredInd>X</ScheduleBNotRequiredInd>
      <WebsiteAddressTxt>SIMIODE.ORG</WebsiteAddressTxt>
      <Organization501c3Ind referenceDocumentId="RetDoc3">X</Organization501c3Ind>
      <TypeOfOrganizationAssocInd>X</TypeOfOrganizationAssocInd>
      <GrossReceiptsAmt>59111</GrossReceiptsAmt>
      <InfoInScheduleOPartIInd>X</InfoInScheduleOPartIInd>
      <ContributionsGiftsGrantsEtcAmt>59111</ContributionsGiftsGrantsEtcAmt>
      <TotalRevenueAmt>59111</TotalRevenueAmt>
      <BenefitsPaidToOrForMembersAmt>7630</BenefitsPaidToOrForMembersAmt>
      <FeesAndOtherPymtToIndCntrctAmt>1040</FeesAndOtherPymtToIndCntrctAmt>
      <PrintingPublicationsPostageAmt>353</PrintingPublicationsPostageAmt>
      <OtherExpensesTotalAmt>38832</OtherExpensesTotalAmt>
      <TotalExpensesAmt>47855</TotalExpensesAmt>
      <ExcessOrDeficitForYearAmt>11256</ExcessOrDeficitForYearAmt>
      <NetAssetsOrFundBalancesBOYAmt>-81136</NetAssetsOrFundBalancesBOYAmt>
      <NetAssetsOrFundBalancesEOYAmt>-69880</NetAssetsOrFundBalancesEOYAmt>
      <InfoInScheduleOPartIIInd>X</InfoInScheduleOPartIIInd>
      <CashSavingsAndInvestmentsGrp>
        <BOYAmt>10812</BOYAmt>
        <EOYAmt>22068</EOYAmt>
      </CashSavingsAndInvestmentsGrp>
      <Form990TotalAssetsGrp>
        <BOYAmt>10812</BOYAmt>
        <EOYAmt>22068</EOYAmt>
      </Form990TotalAssetsGrp>
      <SumOfTotalLiabilitiesGrp>
        <BOYAmt>91948</BOYAmt>
        <EOYAmt>91948</EOYAmt>
      </SumOfTotalLiabilitiesGrp>
      <NetAssetsOrFundBalancesGrp>
        <BOYAmt>-81136</BOYAmt>
        <EOYAmt>-69880</EOYAmt>
      </NetAssetsOrFundBalancesGrp>
      <InfoInScheduleOPartIIIInd>X</InfoInScheduleOPartIIIInd>
      <PrimaryExemptPurposeTxt>SIMIODE IS A SCIENTIFIC EDUCATION ASSOCIATION. THE PURPOSE OF SIMIODE IS TO FOSTER THE TEACHING OF DIFFERENTIAL EQUATIONS, AN UNDERGRADUATE MATHEMATICS COURSE, IN A MANNER THAT USES MODELING AND TECHNOLOGY THROUGHOUT THE LEARNING PROCESS. SIMIODE OFFERS A WEB-BASED COMMUNITY FOR TEACHERS AND LEARNERS AT WWW.SIMIODE.ORG IN SUPPORT OF THAT PURPOSE. THE COMMUNITY OFFERS RESOURCES, REVIEWS, TEACHING MATERIALS, COLLABORATIVE SPACES FOR CREATING TEACHING MATERIALS, AND A PROFESSIONAL, PEER REVIEW SYSTEM FOR PUBLICATION OF TEACHING MATERIALS. IN ADDITION TO THE WEB COMMUNITY, SIMIODE CONDUCTS MINICOURSES AT NATIONAL AND REGIONAL MATHEMATICS ORGANIZATION MEETINGS, RUNS WORKSHOPS FOR TEACHERS TO ENABLE THEM TO LEARN ABOUT THE MODELING-FIRST APPROACH FOR TEACHING DIFFERENTIAL EQUATIONS, AND LEADS PAPER SESSIONS AT MATHEMATICAL SOCIETY MEETINGS. FURTHER, MEMBERS OF THE COMMUNITY ALSO PRESENT CONTRIBUTED PAPERS AT MEETINGS AND PUBLISH SCHOLARLY PAPERS IN THE BROADER PROFESSIONAL LITERATURE, BEYOND</PrimaryExemptPurposeTxt>
      <ProgramSrvcAccomplishmentGrp>
        <DescriptionProgramSrvcAccomTxt>ACHIEVEMENTS FOR THE YEAR: (1) CREATED, EDITED, AND PUBLISHED MATERIAL AT WWW.SIMIODE.ORG IN SUPPORT OF TEACHING DIFFERENTIAL EQUATIONS USING MODELING. (2) RAN MINICOUROSES AND SPONSORED CONTRIBUTED PAPER SESSIONS AT NATIONAL MEETINGS OF THE AMERICAN MATHEMATICS SOCIETY AND THE MATHEMATICAL ASSOCIATION OF AMERICA. (4) PUBLISHED SEVERAL ARTICLES IN JOURNALS AND MAGAZINES RELATED TO OUR MISSION AT SIMIODE. (5) MAINTAINED AN ACTIVE SOCIAL MEDIA CAMPAIGN IN TWITTER, FACEBOOK, AND YOUTUBE IN SUPPORT OF THE SIMIODE COMMUNITY. (6) SOUGHT OUT FUNDING FROM FOUNDATIONS AND CORPORATIONS AND ARE ACTIVELY PURSUING AN INVITATION TO SUBMIT A PROPOSAL FOR 25,000 SUPPORT FROM MOTOROLA SOLUTIONS FOUNDATION.</DescriptionProgramSrvcAccomTxt>
        <ProgramServiceExpensesAmt>47855</ProgramServiceExpensesAmt>
      </ProgramSrvcAccomplishmentGrp>
      <TotalProgramServiceExpensesAmt>47855</TotalProgramServiceExpensesAmt>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>BRIAN J WINKEL</PersonNm>
        <TitleTxt>DIRECTOR</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>000.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <ActivitiesNotPreviouslyRptInd>false</ActivitiesNotPreviouslyRptInd>
      <ChgMadeToOrgnzngDocNotRptInd>false</ChgMadeToOrgnzngDocNotRptInd>
      <OrganizationHadUBIInd>false</OrganizationHadUBIInd>
      <SubjectToProxyTaxInd>false</SubjectToProxyTaxInd>
      <OrganizationDissolvedEtcInd>false</OrganizationDissolvedEtcInd>
      <Form1120PolFiledInd>false</Form1120PolFiledInd>
      <MadeLoansToFromOfficersInd>false</MadeLoansToFromOfficersInd>
      <EngagedInExcessBenefitTransInd>false</EngagedInExcessBenefitTransInd>
      <ProhibitedTaxShelterTransInd>false</ProhibitedTaxShelterTransInd>
      <BooksInCareOfDetail>
        <PersonNm>BRIAN J WINKEL</PersonNm>
        <USAddress>
          <AddressLine1Txt>10460 LOCUST GROVE DR</AddressLine1Txt>
          <CityNm>CHARDON</CityNm>
          <StateAbbreviationCd>OH</StateAbbreviationCd>
          <ZIPCd>44024</ZIPCd>
        </USAddress>
        <PhoneNum>8455687119</PhoneNum>
      </BooksInCareOfDetail>
      <ForeignFinancialAccountInd>false</ForeignFinancialAccountInd>
      <ForeignOfficeInd>false</ForeignOfficeInd>
      <DonorAdvisedFndsInd>false</DonorAdvisedFndsInd>
      <OperateHospitalInd>false</OperateHospitalInd>
      <TanningServicesProvidedInd>false</TanningServicesProvidedInd>
      <RelatedOrganizationCtrlEntInd>false</RelatedOrganizationCtrlEntInd>
      <TransactionWithControlEntInd>false</TransactionWithControlEntInd>
      <PoliticalCampaignActyInd>false</PoliticalCampaignActyInd>
      <LobbyingActivitiesInd>false</LobbyingActivitiesInd>
      <SchoolOperatingInd>false</SchoolOperatingInd>
      <TrnsfrExmptNonChrtblRltdOrgInd>false</TrnsfrExmptNonChrtblRltdOrgInd>
      <PartVIOfCompOfHghstPdEmplTxt>NONE</PartVIOfCompOfHghstPdEmplTxt>
      <PartVIHghstPdCntrctProfSrvcTxt>NONE</PartVIHghstPdCntrctProfSrvcTxt>
      <FiledScheduleAInd>true</FiledScheduleAInd>
    </IRS990EZ>
    <IRS990ScheduleA documentId="RetDoc3">
      <PubliclySupportedOrg509a2Ind>X</PubliclySupportedOrg509a2Ind>
      <GiftsGrantsContrisRcvd509Grp>
        <CurrentTaxYearMinus3YearsAmt>180258</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>15701</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>26279</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>59111</CurrentTaxYearAmt>
        <TotalAmt>281349</TotalAmt>
      </GiftsGrantsContrisRcvd509Grp>
      <Total509Grp>
        <CurrentTaxYearMinus3YearsAmt>180258</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>15701</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>26279</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>59111</CurrentTaxYearAmt>
        <TotalAmt>281349</TotalAmt>
      </Total509Grp>
      <PublicSupportTotal509Amt>281349</PublicSupportTotal509Amt>
      <TotalSupportCalendarYearGrp>
        <CurrentTaxYearMinus3YearsAmt>180258</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>15701</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>26279</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>59111</CurrentTaxYearAmt>
        <TotalAmt>281349</TotalAmt>
      </TotalSupportCalendarYearGrp>
      <PublicSupportCY509Pct>1.00000</PublicSupportCY509Pct>
      <PublicSupportPY509Pct>1.00000</PublicSupportPY509Pct>
      <InvestmentIncomeCYPct>0.00000</InvestmentIncomeCYPct>
      <InvestmentIncomePYPct>0.00000</InvestmentIncomePYPct>
      <ThirtyThrPctSuprtTestsCY509Ind>X</ThirtyThrPctSuprtTestsCY509Ind>
    </IRS990ScheduleA>
    <IRS990ScheduleO documentId="RetDoc2">
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990-EZ, PART I, LINE 16</FormAndLineReferenceDesc>
        <ExplanationTxt>EXPENSES COMPUTER SERVICES 23,208 BANK AND ACCOUNT FEES 467 PAY PAL FEES 497 OFFICE EXPENSE 6,068 SUBCONTRACTORS 8,250 INSURANCE 342 TOTAL 38,832</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990-EZ, PART II, LINE 26</FormAndLineReferenceDesc>
        <ExplanationTxt>UNSECURED NOTES AND LOANS PAYABLE 91,948 91,948</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990-EZ, PART III</FormAndLineReferenceDesc>
        <ExplanationTxt>SIMIODE IS A SCIENTIFIC EDUCATION ASSOCIATION. THE PURPOSE OF SIMIODE IS TO FOSTER THE TEACHING OF DIFFERENTIAL EQUATIONS, AN UNDERGRADUATE MATHEMATICS COURSE, IN A MANNER THAT USES MODELING AND TECHNOLOGY THROUGHOUT THE LEARNING PROCESS. SIMIODE OFFERS A WEB-BASED COMMUNITY FOR TEACHERS AND LEARNERS AT WWW.SIMIODE.ORG IN SUPPORT OF THAT PURPOSE. THE COMMUNITY OFFERS RESOURCES, REVIEWS, TEACHING MATERIALS, COLLABORATIVE SPACES FOR CREATING TEACHING MATERIALS, AND A PROFESSIONAL, PEER REVIEW SYSTEM FOR PUBLICATION OF TEACHING MATERIALS. IN ADDITION TO THE WEB COMMUNITY, SIMIODE CONDUCTS MINICOURSES AT NATIONAL AND REGIONAL MATHEMATICS ORGANIZATION MEETINGS, RUNS WORKSHOPS FOR TEACHERS TO ENABLE THEM TO LEARN ABOUT THE MODELING-FIRST APPROACH FOR TEACHING DIFFERENTIAL EQUATIONS, AND LEADS PAPER SESSIONS AT MATHEMATICAL SOCIETY MEETINGS. FURTHER, MEMBERS OF THE COMMUNITY ALSO PRESENT CONTRIBUTED PAPERS AT MEETINGS AND PUBLISH SCHOLARLY PAPERS IN THE BROADER PROFESSIONAL LITERATURE, BEYOND SIMIODE. SAID ORGANIZATION IS ORGANIZED EXCLUSIVELY FOR EDUCATIONAL AND SCIENTIFIC PURPOSES, INCLUDING, FOR SUCH PURPOSES, THE MAKING OF DISTRIBUTIONS TO ORGANIZATIONS THAT QUALIFY AS EXEMPT ORGANIZATIONS DESCRIBED UNDER SECTION 501(C)(3) OF THE INTERNAL REVENUE CODE, OR CORRESPONDING SECTION OF ANY FUTURE FEDERAL TAX CODE.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990-EZ, PART III, LINE 28</FormAndLineReferenceDesc>
        <ExplanationTxt>ACHIEVEMENTS FOR THE YEAR: (1) CREATED, EDITED, AND PUBLISHED MATERIAL AT WWW.SIMIODE.ORG IN SUPPORT OF TEACHING DIFFERENTIAL EQUATIONS USING MODELING. (2) RAN MINICOUROSES AND SPONSORED CONTRIBUTED PAPER SESSIONS AT NATIONAL MEETINGS OF THE AMERICAN MATHEMATICS SOCIETY AND THE MATHEMATICAL ASSOCIATION OF AMERICA. (4) PUBLISHED SEVERAL ARTICLES IN JOURNALS AND MAGAZINES RELATED TO OUR MISSION AT SIMIODE. (5) MAINTAINED AN ACTIVE SOCIAL MEDIA CAMPAIGN IN TWITTER, FACEBOOK, AND YOUTUBE IN SUPPORT OF THE SIMIODE COMMUNITY. (6) SOUGHT OUT FUNDING FROM FOUNDATIONS AND CORPORATIONS AND ARE ACTIVELY PURSUING AN INVITATION TO SUBMIT A PROPOSAL FOR 25,000 SUPPORT FROM MOTOROLA SOLUTIONS FOUNDATION.</ExplanationTxt>
      </SupplementalInformationDetail>
    </IRS990ScheduleO>
  </ReturnData>
</Return>
