problem of the month: first rate - inside mathematics

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Problem of the Month First Rate © Noyce Foundation 2015. This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 Unported License (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en_US). 1 Problem of the Month: First Rate The Problems of the Month (POM) are used in a variety of ways to promote problem solving and to foster the first standard of mathematical practice from the Common Core State Standards: “Make sense of problems and persevere in solving them.” The POM may be used by a teacher to promote problem solving and to address the differentiated needs of her students. A department or grade level may engage their students in a POM to showcase problem solving as a key aspect of doing mathematics. POMs can also be used school wide to promote a problem-solving theme at a school. The goal is for all students to have the experience of attacking and solving non-routine problems and developing their mathematical reasoning skills. Although obtaining and justifying solutions to the problems is the objective, the process of learning to problem solve is even more important. The Problem of the Month is structured to provide reasonable tasks for all students in a school. The POM is structured with a shallow floor and a high ceiling, so that all students can productively engage, struggle, and persevere. The Primary Version is designed to be accessible to all students and especially as the key challenge for grades K – 1. Level A will be challenging for most second and third graders. Level B may be the limit of where fourth and fifth-grade students have success and understanding. Level C may stretch sixth and seventh-grade students. Level D may challenge most eighth and ninth-grade students, and Level E should be challenging for most high school students. These grade-level expectations are just estimates and should not be used as an absolute minimum expectation or maximum limitation for students. Problem solving is a learned skill, and students may need many experiences to develop their reasoning skills, approaches, strategies, and the perseverance to be successful. The Problem of the Month builds on sequential levels of understanding. All students should experience Level A and then move through the tasks in order to go as deeply as they can into the problem. There will be those students who will not have access into even Level A. Educators should feel free to modify the task to allow access at some level. Overview In the Problem of the Month First Rate, students use measurement, rates of change, and algebraic thinking to solve problems involving proportional relationships, metrics, and multiplicative relationships. The mathematical topics that underlie this POM are repeated addition, multiplication, division, percents, linear measurement, proportional reasoning, rates, distance-time-velocity, change, functions, algebraic reasoning, and related rates. In the first levels of the POM, students are presented with a measurement problem. In the problem, students are asked to determine who wins a race between two brothers jumping up the stairway, where one jumps farther than the other. The

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Page 1: Problem of the Month: First Rate - Inside Mathematics

ProblemoftheMonth FirstRate©NoyceFoundation2015.ThisworkislicensedunderaCreativeCommonsAttribution-NonCommercial-NoDerivatives3.0UnportedLicense(http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en_US).

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ProblemoftheMonth:FirstRate

TheProblemsoftheMonth(POM)areusedinavarietyofwaystopromoteproblemsolvingandtofosterthefirststandardofmathematicalpracticefromtheCommonCoreStateStandards:“Makesenseofproblemsandpersevereinsolvingthem.”ThePOMmaybeusedbyateachertopromoteproblemsolvingandtoaddressthedifferentiatedneedsofherstudents.AdepartmentorgradelevelmayengagetheirstudentsinaPOMtoshowcaseproblemsolvingasakeyaspectofdoingmathematics.POMscanalsobeusedschoolwidetopromoteaproblem-solvingthemeataschool.Thegoalisforallstudentstohavetheexperienceofattackingandsolvingnon-routineproblemsanddevelopingtheirmathematicalreasoningskills.Althoughobtainingandjustifyingsolutionstotheproblemsistheobjective,theprocessoflearningtoproblemsolveisevenmoreimportant.TheProblemoftheMonthisstructuredtoprovidereasonabletasksforallstudentsinaschool.ThePOMisstructuredwithashallowfloorandahighceiling,sothatallstudentscanproductivelyengage,struggle,andpersevere.ThePrimaryVersionisdesignedtobeaccessibletoallstudentsandespeciallyasthekeychallengeforgradesK–1.LevelAwillbechallengingformostsecondandthirdgraders.LevelBmaybethelimitofwherefourthandfifth-gradestudentshavesuccessandunderstanding.LevelCmaystretchsixthandseventh-gradestudents.LevelDmaychallengemosteighthandninth-gradestudents,andLevelEshouldbechallengingformosthighschoolstudents.Thesegrade-levelexpectationsarejustestimatesandshouldnotbeusedasanabsoluteminimumexpectationormaximumlimitationforstudents.Problemsolvingisalearnedskill,andstudentsmayneedmanyexperiencestodeveloptheirreasoningskills,approaches,strategies,andtheperseverancetobesuccessful.TheProblemoftheMonthbuildsonsequentiallevelsofunderstanding.AllstudentsshouldexperienceLevelAandthenmovethroughthetasksinordertogoasdeeplyastheycanintotheproblem.TherewillbethosestudentswhowillnothaveaccessintoevenLevelA.Educatorsshouldfeelfreetomodifythetasktoallowaccessatsomelevel.OverviewIntheProblemoftheMonthFirstRate,studentsusemeasurement,ratesofchange,andalgebraicthinkingtosolveproblemsinvolvingproportionalrelationships,metrics,andmultiplicativerelationships.ThemathematicaltopicsthatunderliethisPOMarerepeatedaddition,multiplication,division,percents,linearmeasurement,proportionalreasoning,rates,distance-time-velocity,change,functions,algebraicreasoning,andrelatedrates.InthefirstlevelsofthePOM,studentsarepresentedwithameasurementproblem.Intheproblem,studentsareaskedtodeterminewhowinsaracebetweentwobrothersjumpingupthestairway,whereonejumpsfartherthantheother.The

Page 2: Problem of the Month: First Rate - Inside Mathematics

ProblemoftheMonth FirstRate©NoyceFoundation2015.ThisworkislicensedunderaCreativeCommonsAttribution-NonCommercial-NoDerivatives3.0UnportedLicense(http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en_US).

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studentshavetoreasonbetweennumberofjumpsandlengthofjumps.InLevelB,studentsarechallengedwithaprobleminvolvingtworunnerswhorundifferentdistancesfordifferenttimes.Theywillneedtoreasonabouttherelationshipbetweenthetworatestodeterminewhoisfaster.InLevelC,thestudentsarepresentedwiththechallengeofdetermininghowtwostudentsworkingtogetheratdifferentratescanworktogethertocompleteatask.Thestudentsareaskedtodeterminehowfastthetaskcanbecompleted.InLevelD,studentsanalyzetrackraceswhererunnersarerunningatdifferentpaces.Thestudentsinvestigatewhenarunnerneedstomakeachangeinordertoovertakearunnerinfrontofhim.InthefinallevelofthePOM,studentsarepresentedwithasituationthatinvolvesrelatedratesinthecontextofafootballgame.Studentsareaskedtodeterminethetimeandspeedafootballmustbethrowntocompleteapasstothetightend.MathematicalConceptsThemajormathematicalideasofthisPOMaremeasurement,proportionalreasoningandrateofchange.Studentsusemeasuringtechniques,addition,multiplication,division,andrepresentationsofrationalnumberssuchasfractions,decimals,andpercents,aswellasratios,proportion,rates,equations,andlinearfunctions.Studentssolveproblemsinvolvingratesforcompletingajob,aswellasdistance,rateandtime

Page 3: Problem of the Month: First Rate - Inside Mathematics

Problem of the Month First Rate Page 1 ©NoyceFoundation2015.ThisworkislicensedunderaCreativeCommonsAttribution-NonCommercial-NoDerivatives3.0UnportedLicense(http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en_US).

ProblemoftheMonth

FirstRateLevelADylanandAustinarebrothers.Theyplayaracinggameonthestairs.Theyjumpandlandontwofeetastheyraceupthestaircase.WhenAustinjumps,helandsoneachstep.WhenDylanjumps,heskipsastepandlandsoneveryotherstep.

1. Whohastotakemorejumpstogettothetopofthestairs?2. WhenDylanjumpsupthestaircase,howmanyjumpsdoeshemake?3. WhenAustinjumpsupthestaircase,howmanyjumpsdoeshemake?4. IfAustinandDylaneachtook5jumps,whowouldbefurtherupthestairs?5. Attheendoftheracewhotooklessjumps?6. Whodoyouthinkwontherace?Explainyouranswer.

Page 4: Problem of the Month: First Rate - Inside Mathematics

Problem of the Month First Rate Page 2 ©NoyceFoundation2015.ThisworkislicensedunderaCreativeCommonsAttribution-NonCommercial-NoDerivatives3.0UnportedLicense(http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en_US).

LevelBTomandDianestartedtorace.Tomtook4secondstorun6yards.Dianeran5yardsin3seconds.

Iftheycontinuedtorunatthesamespeeds,whowouldgetto30yardsfirst?Showhowyoufiguredoutyouranswer.Whorunsfaster?Howcanyoucomparetheirspeeds?

Page 5: Problem of the Month: First Rate - Inside Mathematics

Problem of the Month First Rate Page 3 ©NoyceFoundation2015.ThisworkislicensedunderaCreativeCommonsAttribution-NonCommercial-NoDerivatives3.0UnportedLicense(http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en_US).

LevelCTheEnvironmentalClubatschoolattendsanannualcommunityclean-upevent.Theyhaverecyclinggames.Ateamisassignedanareaoflandthatisscatteredwithlitter.Thegoalisforapairofparticipantstocleanuptheareainthefastesttimepossible.

Tammy,workingalone, could cleanone-half thearea inonehour.Herpartner,Melissa -workingalone-couldcleanone-thirdoftheareainonehour.Duringthecontestwhentheyworktogether,howlongwill it takethemtocleanthearea?Explainhowyoufoundyoursolution.

Page 6: Problem of the Month: First Rate - Inside Mathematics

Problem of the Month First Rate Page 4 ©NoyceFoundation2015.ThisworkislicensedunderaCreativeCommonsAttribution-NonCommercial-NoDerivatives3.0UnportedLicense(http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en_US).

Level D YouareanOlympicrunner.Youhave justqualified tobe in the finalsof the1,500-meterrace. The track is 400meters in an oval shape. The race is three and three-fourths lapsaroundthetrack.

The favorite to win the race is a Kenyan who holds the current best time, which is 3minutes29.4seconds.TheKenyanrunsaverysteadyrace.EachoftheKenyan’slaptimes(400meters)iswithinasecondofeachother.Yourunacompletelydifferenttypeofrace.Youhaveaverystrongkick,whichmeansyouusuallylagbehindforthefirstthreelapstosaveenergy,andthenwhentheleaderhas300meterstogoyoupouritontowinatthetape.Youliketosaveenergyinthefirstthreelaps,butyoudon’twanttobemorethan50metersbehindwhenyoustartyourkicktothefinishline.Determineyourstrategytowinthisrace.Whatistheaveragespeedyouneedtorunduringthe firstpartof therace?What is theaveragespeedyouneedtorunduringyourkicktowintherace?HowmightyourracechangeiftheKenyanrunstwosecondsfaster?

Start ->

Finish

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Problem of the Month First Rate Page 5 ©NoyceFoundation2015.ThisworkislicensedunderaCreativeCommonsAttribution-NonCommercial-NoDerivatives3.0UnportedLicense(http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en_US).

Level E It’s the third quarter, with ten yards to go for a first down. The quarterback calls hisfavoriteplay,arollouttotherightandasquare-outpasstohistightend.Seethediagramoftheplaybelow:On the snap from center, the tight end runs straight ahead for ten yards,makes a sharpright turn and runs toward the side lines. The quarterback rolls to his right and stopsdirectlybehindwherethetightendbegan,butsixyardsbehindthelineofscrimmage.Thequarterbackdoesnotmakethepassuntilafterthetightendmakeshisbreaktowardthesidelines.The tight end is running toward the sideline at a speedof8 yardsper second.Thequarterbacktracksthereceiver,decidingwhentothrowthepassandtheflightpathofthe ball. If the tight end makes the catch 12 yards after the break, how far does thequarterbackthrowthepass(inastraightline)andatwhatrateisthedistancebetweenthereceiverandquarterbackchanging?Suppose thequarterback threwthepasssooner,and thereceiver ranat thesamespeed.Thedistancetheballtraveledwas17.3yards.Howmanyyardsafterthebreakwastheballcaughtandatwhatratewasthedistancebetweenthereceiverandquarterbackchanging?Giventheconstantspeedofthereceiver,considerseverallocationswherethesquare-outpasscouldbecompleted.Explaintherelationshipbetweenthespotofthecompletion,thedistanceofthepass,andatwhatratethedistancebetweenthereceiverandquarterbackischanging?

Page 8: Problem of the Month: First Rate - Inside Mathematics

Problem of the Month First Rate Page 6 ©NoyceFoundation2015.ThisworkislicensedunderaCreativeCommonsAttribution-NonCommercial-NoDerivatives3.0UnportedLicense(http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en_US).

ProblemoftheMonthFirstRate

PrimaryVersion

Materials:Apictureofthestaircasewithfootprints,tape,measuringtape,paperandpencil.Discussionontherug:Teacherusestapetomaketwomarksontheflooraboutfiveyardsapart.Theteacherchoosestwoclassmatestostartatonemarkandmakeonejumptoward theothermarkwithboth feet together.The students jumpand the teacherasks, “Who jumped farther?” One at a time, the students jump until they reach the secondmark as the class counts. The teacher asks, “Who took the most jumps?” The teacherholdsupthepicturesof thestaircaseandthewet footprintandasks, “Who can tell me what they see in this picture?” The students respond. “This is a picture of a jumping race up the stairs. Two boys, both with wet feet race up the stairs. They jump landing on two feet as they race up the staircase. When the first boy jumps, he lands on each step. When the second boy jumps, he skips a step and lands on every other step.” In small groups: Each student has access to the picture of the staircase, paper andpencil. Theteacherexplainsthattheyneedtothinkaboutthejumpingraceupthestairs.Theteacherasksthefollowingquestions: “Who jumps farther? Who takes more jumps? How many jumps does the first boy take? Who do you think won the race? At the end of the investigation have students either discuss or dictate a response to theprompt:“Tell me how you know who won the race.”

Page 9: Problem of the Month: First Rate - Inside Mathematics

Problem of the Month First Rate Page 7 ©NoyceFoundation2015.ThisworkislicensedunderaCreativeCommonsAttribution-NonCommercial-NoDerivatives3.0UnportedLicense(http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en_US).

First Boy

Second Boy

Page 10: Problem of the Month: First Rate - Inside Mathematics

CCSSMAlignment:ProblemoftheMonth FirstRate©NoyceFoundation2015.ThisworkislicensedunderaCreativeCommonsAttribution-NonCommercial-NoDerivatives3.0UnportedLicense(http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en_US).

ProblemoftheMonth

FirstRateTaskDescription–LevelA

Thistaskchallengesstudentstodeterminewhowinsaracebetweentwobrothersjumpingupthestairwaywhereonebrotherjumpsfartherthantheother.Thestudenthastoreasonbetweennumberofjumpsandlengthofjumps.

CommonCoreStateStandardsMath-ContentStandardsMeasurementandDataDescribeandcomparemeasurableattributes.K.MD.1Describemeasurableattributesofobjects,suchaslengthorweight.Describeseveralmeasurableattributesofasingleobject.K.MD.2Directlycomparetwoobjectswithameasurableattributeincommon,toseewhichobjecthas“moreof”/“lessof”theattribute,anddescribethedifference.Forexample,directlycomparetheheightsoftwochildrenanddescribeonechildastaller/shorter.Measurelengthsindirectlyandbyiteratinglengthunits.1.MD.2Expressthelengthofanobjectasawholenumberoflengthunits,bylayingmultiplecopiesofashorterobject(thelengthunit)endtoend;understandthatthelengthmeasurementofanobjectisthenumberofsame-sizelengthunitsthatspanitwithnogapsoroverlaps.Limittocontextswheretheobjectbeingmeasuredisspannedbyawholenumberoflengthunitswithnogapsoroverlaps.

CommonCoreStateStandardsMath–StandardsofMathematicalPracticeMP.2Reasonabstractlyandquantitatively.Mathematicallyproficientstudentsmakesenseofquantitiesandtheirrelationshipsinproblemsituations.Theybringtwocomplementaryabilitiestobearonproblemsinvolvingquantitativerelationships:theabilitytodecontextualize—toabstractagivensituationandrepresentitsymbolicallyandmanipulatetherepresentingsymbolsasiftheyhavealifeoftheirown,withoutnecessarilyattendingtotheirreferents—andtheabilitytocontextualize,topauseasneededduringthemanipulationprocessinordertoprobeintothereferentsforthesymbolsinvolved.Quantitativereasoningentailshabitsofcreatingacoherentrepresentationoftheproblemathand;consideringtheunitsinvolved;attendingtothemeaningofquantities,notjusthowtocomputethem;andknowingandflexiblyusingdifferentpropertiesofoperationsandobjects.MP.5 Useappropriatetoolsstrategically.Mathematicallyproficientstudentsconsidertheavailabletoolswhensolvingamathematicalproblem.Thesetoolsmightincludepencilandpaper,concretemodels,aruler,aprotractor,acalculator,aspreadsheet,acomputeralgebrasystem,astatisticalpackage,ordynamicgeometrysoftware.Proficientstudentsaresufficientlyfamiliarwithtoolsappropriatefortheirgradeorcoursetomakesounddecisionsaboutwheneachofthesetoolsmightbehelpful,recognizingboththeinsighttobegainedandtheirlimitations.Forexample,mathematicallyproficienthighschoolstudentsanalyzegraphsoffunctionsandsolutionsgeneratedusingagraphingcalculator.Theydetectpossibleerrorsbystrategicallyusingestimationandothermathematicalknowledge.Whenmakingmathematicalmodels,theyknowthattechnologycanenablethemtovisualizetheresultsofvaryingassumptions,exploreconsequences,andcomparepredictionswithdata.Mathematicallyproficientstudentsatvariousgradelevelsareabletoidentifyrelevantexternalmathematicalresources,suchasdigitalcontentlocatedonawebsite,andusethemtoposeorsolveproblems.Theyareabletousetechnologicaltoolstoexploreanddeepentheirunderstandingofconcepts.

Page 11: Problem of the Month: First Rate - Inside Mathematics

CCSSMAlignment:ProblemoftheMonth FirstRate©NoyceFoundation2015.ThisworkislicensedunderaCreativeCommonsAttribution-NonCommercial-NoDerivatives3.0UnportedLicense(http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en_US).

ProblemoftheMonth

FirstRateTaskDescription–LevelB

Thistaskchallengesstudentstoanalyzeaproblemwheretworunnersrundifferentdistancesindifferenttimes.Thestudentswillneedtoreasonabouttherelationshipbetweenthetworatestodeterminewhoisfaster.

CommonCoreStateStandardsMath-ContentStandardsMeasurementandDataMeasureandestimatelengthsinstandardunits.2.MD.4Measuretodeterminehowmuchlongeroneobjectisthananother,expressingthelengthdifferenceintermsofastandardlengthunit.RatiosandProportionalRelationshipsUnderstandratioconceptsanduseratioreasoningtosolveproblems.6.RP.1Understandtheconceptofaratioanduseratiolanguagetodescribearatiorelationshipbetweentwoquantities.Forexample,“Theratioofwingstobeaksinthebirdhouseatthezoowas2:1,becauseforevery2wingstherewas1beak.”“ForeveryvotecandidateAreceived,candidateCreceivednearlythreevotes.”6.RP.2Understandtheconceptofaunitratea/bassociatedwitharatioa:bwithb= ̸0,anduseratelanguageinthecontextofaratiorelationship.Forexample,“Thisrecipehasaratioof3cupsofflourto4cupsofsugar,sothereis3/4cupofflourforeachcupofsugar.”“Wepaid$75for15hamburgers,whichisarateof$5perhamburger.”16.RP.3Useratioandratereasoningtosolvereal-worldandmathematicalproblems,e.g.,byreasoningabouttablesofequivalentratios,tapediagrams,doublenumberlinediagrams,orequations.6.RP.3a.Maketablesofequivalentratiosrelatingquantitieswithwhole-numbermeasurements,findmissingvaluesinthetables,andplotthepairsofvaluesonthecoordinateplane.Usetablestocompareratios.6.RP.3b.Solveunitrateproblemsincludingthoseinvolvingunitpricingandconstantspeed.Forexample,ifittook7hourstomow4lawns,thenatthatrate,howmanylawnscouldbemowedin35hours?Atwhatratewerelawnsbeingmowed?Analyzeproportionalrelationshipsandusethemtosolvereal-worldandmathematicalproblems.7.RP.1Computeunitratesassociatedwithratiosoffractions,includingratiosoflengths,areasandotherquantitiesmeasuredinlikeordifferentunits.Forexample,ifapersonwalks1/2mileineach1/4hour,computetheunitrateasthecomplexfraction1/2/1/4milesperhour,equivalently2milesperhour.7.RP.2Recognizeandrepresentproportionalrelationshipsbetweenquantities.7.RP.2a.Decidewhethertwoquantitiesareinaproportionalrelationship,e.g.,bytestingforequivalentratiosinatableorgraphingonacoordinateplaneandobservingwhetherthegraphisastraightlinethroughtheorigin.7.RP.2b.Identifytheconstantofproportionality(unitrate)intables,graphs,equations,diagrams,andverbaldescriptionsofproportionalrelationships.7.RP.2c.Representproportionalrelationshipsbyequations.Forexample,iftotalcosttisproportionaltothenumbernofitemspurchasedataconstantpricep,therelationshipbetweenthetotalcostandthenumberofitemscanbeexpressedast=pn.

CommonCoreStateStandardsMath–StandardsofMathematicalPracticeMP.2Reasonabstractlyandquantitatively.Mathematicallyproficientstudentsmakesenseofquantitiesandtheirrelationshipsinproblemsituations.Theybringtwocomplementaryabilitiestobearonproblemsinvolvingquantitativerelationships:theabilitytodecontextualize—toabstractagivensituationandrepresentitsymbolicallyandmanipulatetherepresentingsymbolsasiftheyhavealifeoftheirown,withoutnecessarilyattendingtotheirreferents—andtheabilitytocontextualize,topauseasneededduringthemanipulationprocessinordertoprobeintothereferentsforthesymbolsinvolved.Quantitativereasoningentailshabitsofcreatingacoherentrepresentationoftheproblemathand;consideringtheunitsinvolved;attendingtothemeaningofquantities,notjusthowtocomputethem;andknowingandflexiblyusingdifferentpropertiesofoperationsandobjects.MP.5 Useappropriatetoolsstrategically.Mathematicallyproficientstudentsconsidertheavailabletoolswhensolvingamathematicalproblem.Thesetoolsmightincludepencilandpaper,concretemodels,aruler,aprotractor,acalculator,aspreadsheet,acomputeralgebrasystem,astatisticalpackage,ordynamicgeometrysoftware.Proficientstudentsaresufficientlyfamiliarwithtoolsappropriatefortheirgradeorcoursetomakesounddecisionsaboutwheneachofthesetoolsmightbehelpful,recognizingboththeinsighttobegainedandtheirlimitations.Forexample,mathematicallyproficienthighschoolstudentsanalyzegraphsoffunctionsandsolutionsgeneratedusingagraphingcalculator.Theydetectpossibleerrorsbystrategicallyusingestimationandothermathematicalknowledge.Whenmakingmathematicalmodels,theyknowthattechnologycanenablethemtovisualizetheresultsofvaryingassumptions,exploreconsequences,andcomparepredictionswithdata.Mathematicallyproficientstudentsatvariousgradelevelsareabletoidentifyrelevantexternalmathematicalresources,suchasdigitalcontentlocatedonawebsite,andusethemtoposeorsolveproblems.Theyareabletousetechnologicaltoolstoexploreanddeepentheirunderstandingofconcepts.

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CCSSMAlignment:ProblemoftheMonth FirstRate©NoyceFoundation2015.ThisworkislicensedunderaCreativeCommonsAttribution-NonCommercial-NoDerivatives3.0UnportedLicense(http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en_US).

ProblemoftheMonth

FirstRateTaskDescription–LevelC

Thistaskchallengesstudentstodeterminehowtwostudentsworkingatdifferentratescanworktogethertocompleteataskandhowfastthetaskcanbecompleted.

CommonCoreStateStandardsMath-ContentStandardsRatiosandProportionalRelationshipsUnderstandratioconceptsanduseratioreasoningtosolveproblems.6.RP.2Understandtheconceptofaunitratea/bassociatedwitharatioa:bwithb= ̸0,anduseratelanguageinthecontextofaratiorelationship.Forexample,“Thisrecipehasaratioof3cupsofflourto4cupsofsugar,sothereis3/4cupofflourforeachcupofsugar.”“Wepaid$75for15hamburgers,whichisarateof$5perhamburger.”6.RP.3Useratioandratereasoningtosolvereal-worldandmathematicalproblems,e.g.,byreasoningabouttablesofequivalentratios,tapediagrams,doublenumberlinediagrams,orequations.6.RP.3a.Maketablesofequivalentratiosrelatingquantitieswithwhole-numbermeasurements,findmissingvaluesinthetables,andplotthepairsofvaluesonthecoordinateplane.Usetablestocompareratios.6RP.3b.Solveunitrateproblemsincludingthoseinvolvingunitpricingandconstantspeed.Forexample,ifittook7hourstomow4lawns,thenatthatrate,howmanylawnscouldbemowedin35hours?Atwhatratewerelawnsbeingmowed?6.RP.3c.Findapercentofaquantityasarateper100(e.g.,30%ofaquantitymeans30/100timesthequantity);solveproblemsinvolvingfindingthewhole,givenapartandthepercent.6.RP.3d.Useratioreasoningtoconvertmeasurementunits;manipulateandtransformunitsappropriatelywhenmultiplyingordividingquantities.Analyzeproportionalrelationshipsandusethemtosolvereal-worldandmathematicalproblems.7.RP.1Computeunitratesassociatedwithratiosoffractions,includingratiosoflengths,areasandotherquantitiesmeasuredinlikeordifferentunits.Forexample,ifapersonwalks1/2mileineach1/4hour,computetheunitrateasthecomplexfraction1/2/1/4milesperhour,equivalently2milesperhour.

CommonCoreStateStandardsMath–StandardsofMathematicalPracticeMP.2Reasonabstractlyandquantitatively.Mathematicallyproficientstudentsmakesenseofquantitiesandtheirrelationshipsinproblemsituations.Theybringtwocomplementaryabilitiestobearonproblemsinvolvingquantitativerelationships:theabilitytodecontextualize—toabstractagivensituationandrepresentitsymbolicallyandmanipulatetherepresentingsymbolsasiftheyhavealifeoftheirown,withoutnecessarilyattendingtotheirreferents—andtheabilitytocontextualize,topauseasneededduringthemanipulationprocessinordertoprobeintothereferentsforthesymbolsinvolved.Quantitativereasoningentailshabitsofcreatingacoherentrepresentationoftheproblemathand;consideringtheunitsinvolved;attendingtothemeaningofquantities,notjusthowtocomputethem;andknowingandflexiblyusingdifferentpropertiesofoperationsandobjects.MP.5 Useappropriatetoolsstrategically.Mathematicallyproficientstudentsconsidertheavailabletoolswhensolvingamathematicalproblem.Thesetoolsmightincludepencilandpaper,concretemodels,aruler,aprotractor,acalculator,aspreadsheet,acomputeralgebrasystem,astatisticalpackage,ordynamicgeometrysoftware.Proficientstudentsaresufficientlyfamiliarwithtoolsappropriatefortheirgradeorcoursetomakesounddecisionsaboutwheneachofthesetoolsmightbehelpful,recognizingboththeinsighttobegainedandtheirlimitations.Forexample,mathematicallyproficienthighschoolstudentsanalyzegraphsoffunctionsandsolutionsgeneratedusingagraphingcalculator.Theydetectpossibleerrorsbystrategicallyusingestimationandothermathematicalknowledge.Whenmakingmathematicalmodels,theyknowthattechnologycanenablethemtovisualizetheresultsofvaryingassumptions,exploreconsequences,andcomparepredictionswithdata.Mathematicallyproficientstudentsatvariousgradelevelsareabletoidentifyrelevantexternalmathematicalresources,suchasdigitalcontentlocatedonawebsite,andusethemtoposeorsolveproblems.Theyareabletousetechnologicaltoolstoexploreanddeepentheirunderstandingofconcepts.

Page 13: Problem of the Month: First Rate - Inside Mathematics

CCSSMAlignment:ProblemoftheMonth FirstRate©NoyceFoundation2015.ThisworkislicensedunderaCreativeCommonsAttribution-NonCommercial-NoDerivatives3.0UnportedLicense(http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en_US).

ProblemoftheMonth:

FirstRateTaskDescription–LevelD

Thistaskchallengesstudentstoanalyzetrackraceswhererunnersarerunningatdifferentpaces.Studentsmustinvestigatewhenarunnerneedstomakeachangetoovertaketherunnerinthefront.

CommonCoreStateStandardsMath-ContentStandardsRatiosandProportionalRelationshipsUnderstandratioconceptsanduseratioreasoningtosolveproblems.6.RP.3Useratioandratereasoningtosolvereal-worldandmathematicalproblems,e.g.,byreasoningabouttablesofequivalentratios,tapediagrams,doublenumberlinediagrams,orequations.6.RP.3a.Maketablesofequivalentratiosrelatingquantitieswithwhole-numbermeasurements,findmissingvaluesinthetables,andplotthepairsofvaluesonthecoordinateplane.Usetablestocompareratios.6.RP.3b.Solveunitrateproblemsincludingthoseinvolvingunitpricingandconstantspeed.Forexample,ifittook7hourstomow4lawns,thenatthatrate,howmanylawnscouldbemowedin35hours?Atwhatratewerelawnsbeingmowed?6.RP.3c.Findapercentofaquantityasarateper100(e.g.,30%ofaquantitymeans30/100timesthequantity);solveproblemsinvolvingfindingthewhole,givenapartandthepercent.6.RP.3d.Useratioreasoningtoconvertmeasurementunits;manipulateandtransformunitsappropriatelywhenmultiplyingordividingquantities.Analyzeproportionalrelationshipsandusethemtosolvereal-worldandmathematicalproblems.7.RP.1Computeunitratesassociatedwithratiosoffractions,includingratiosoflengths,areasandotherquantitiesmeasuredinlikeordifferentunits.Forexample,ifapersonwalks1/2mileineach1/4hour,computetheunitrateasthecomplexfraction1/2/1/4milesperhour,equivalently2milesperhour.7.RP.3Useproportionalrelationshipstosolvemultistepratioandpercentproblems.

CommonCoreStateStandardsMath–StandardsofMathematicalPracticeMP.2Reasonabstractlyandquantitatively.Mathematicallyproficientstudentsmakesenseofquantitiesandtheirrelationshipsinproblemsituations.Theybringtwocomplementaryabilitiestobearonproblemsinvolvingquantitativerelationships:theabilitytodecontextualize—toabstractagivensituationandrepresentitsymbolicallyandmanipulatetherepresentingsymbolsasiftheyhavealifeoftheirown,withoutnecessarilyattendingtotheirreferents—andtheabilitytocontextualize,topauseasneededduringthemanipulationprocessinordertoprobeintothereferentsforthesymbolsinvolved.Quantitativereasoningentailshabitsofcreatingacoherentrepresentationoftheproblemathand;consideringtheunitsinvolved;attendingtothemeaningofquantities,notjusthowtocomputethem;andknowingandflexiblyusingdifferentpropertiesofoperationsandobjects.MP.5 Useappropriatetoolsstrategically.Mathematicallyproficientstudentsconsidertheavailabletoolswhensolvingamathematicalproblem.Thesetoolsmightincludepencilandpaper,concretemodels,aruler,aprotractor,acalculator,aspreadsheet,acomputeralgebrasystem,astatisticalpackage,ordynamicgeometrysoftware.Proficientstudentsaresufficientlyfamiliarwithtoolsappropriatefortheirgradeorcoursetomakesounddecisionsaboutwheneachofthesetoolsmightbehelpful,recognizingboththeinsighttobegainedandtheirlimitations.Forexample,mathematicallyproficienthighschoolstudentsanalyzegraphsoffunctionsandsolutionsgeneratedusingagraphingcalculator.Theydetectpossibleerrorsbystrategicallyusingestimationandothermathematicalknowledge.Whenmakingmathematicalmodels,theyknowthattechnologycanenablethemtovisualizetheresultsofvaryingassumptions,exploreconsequences,andcomparepredictionswithdata.Mathematicallyproficientstudentsatvariousgradelevelsareabletoidentifyrelevantexternalmathematicalresources,suchasdigitalcontentlocatedonawebsite,andusethemtoposeorsolveproblems.Theyareabletousetechnologicaltoolstoexploreanddeepentheirunderstandingofconcepts.

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ProblemoftheMonth

FirstRateTaskDescription–LevelE

Thistaskchallengesstudentstodeterminethetimeandspeedafootballmustbethrowntocompleteapasstoatightendwhenpresentedwithasituationthatinvolvesrelatedratesinthecontextofafootballgame.

CommonCoreStateStandardsMath-ContentStandardsGeometryUnderstandandapplythePythagoreanTheorem.8.G.7ApplythePythagoreanTheoremtodetermineunknownsidelengthsinrighttrianglesinreal-worldandmathematicalproblemsintwoandthreedimensions.HighSchool–Functions-BuildingFunctionsBuildafunctionthatmodelsarelationshipbetweentwoquantitiesF-BF.1Writeafunctionthatdescribesarelationshipbetweentwoquantities.★F-BF.1c.(+)Composefunctions.Forexample,ifT(y)isthetemperatureintheatmosphereasafunctionofheight,andh(t)istheheightofaweatherballoonasafunctionoftime,thenT(h(t))isthetemperatureatthelocationoftheweatherballoonasafunctionoftime.HighSchool–Functions-Linear,Quadratic,andExponentialModelsConstructandcomparelinear,quadratic,andexponentialmodelsandsolveproblems.Interpretexpressionsforfunctionsintermsofthesituationtheymodel.F-LE.1Distinguishbetweensituationsthatcanbemodeledwithlinearfunctionsandwithexponentialfunctions.

CommonCoreStateStandardsMath–StandardsofMathematicalPracticeMP.2Reasonabstractlyandquantitatively.Mathematicallyproficientstudentsmakesenseofquantitiesandtheirrelationshipsinproblemsituations.Theybringtwocomplementaryabilitiestobearonproblemsinvolvingquantitativerelationships:theabilitytodecontextualize—toabstractagivensituationandrepresentitsymbolicallyandmanipulatetherepresentingsymbolsasiftheyhavealifeoftheirown,withoutnecessarilyattendingtotheirreferents—andtheabilitytocontextualize,topauseasneededduringthemanipulationprocessinordertoprobeintothereferentsforthesymbolsinvolved.Quantitativereasoningentailshabitsofcreatingacoherentrepresentationoftheproblemathand;consideringtheunitsinvolved;attendingtothemeaningofquantities,notjusthowtocomputethem;andknowingandflexiblyusingdifferentpropertiesofoperationsandobjects.MP.4 Modelwithmathematics.Mathematicallyproficientstudentscanapplythemathematicstheyknowtosolveproblemsarisingineverydaylife,society,andtheworkplace.Inearlygrades,thismightbeassimpleaswritinganadditionequationtodescribeasituation.Inmiddlegrades,astudentmightapplyproportionalreasoningtoplanaschooleventoranalyzeaprobleminthecommunity.Byhighschool,astudentmightusegeometrytosolveadesignproblemoruseafunctiontodescribehowonequantityofinterestdependsonanother.Mathematicallyproficientstudentswhocanapplywhattheyknowarecomfortablemakingassumptionsandapproximationstosimplifyacomplicatedsituation,realizingthatthesemayneedrevisionlater.Theyareabletoidentifyimportantquantitiesinapracticalsituationandmaptheirrelationshipsusingsuchtoolsasdiagrams,two-waytables,graphs,flowchartsandformulas.Theycananalyzethoserelationshipsmathematicallytodrawconclusions.Theyroutinelyinterprettheirmathematicalresultsinthecontextofthesituationandreflectonwhethertheresultsmakesense,possiblyimprovingthemodelifithasnotserveditspurpose.MP.5 Useappropriatetoolsstrategically.Mathematicallyproficientstudentsconsidertheavailabletoolswhensolvingamathematicalproblem.Thesetoolsmightincludepencilandpaper,concretemodels,aruler,aprotractor,acalculator,aspreadsheet,acomputeralgebrasystem,astatisticalpackage,ordynamicgeometrysoftware.Proficientstudentsaresufficientlyfamiliarwithtoolsappropriatefortheirgradeorcoursetomakesounddecisionsaboutwheneachofthesetoolsmightbehelpful,recognizingboththeinsighttobegainedandtheirlimitations.Forexample,mathematicallyproficienthighschoolstudentsanalyzegraphsoffunctionsandsolutionsgeneratedusingagraphingcalculator.Theydetectpossibleerrorsbystrategicallyusingestimationandothermathematicalknowledge.Whenmakingmathematicalmodels,theyknowthattechnologycanenablethemtovisualizetheresultsofvaryingassumptions,exploreconsequences,andcomparepredictionswithdata.Mathematicallyproficientstudentsatvariousgradelevelsareabletoidentifyrelevantexternalmathematicalresources,suchasdigitalcontentlocatedonawebsite,andusethemtoposeorsolveproblems.Theyareabletousetechnologicaltoolstoexploreanddeepentheirunderstandingofconcepts.

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ProblemoftheMonth

FirstRateTaskDescription–PrimaryLevel

Thistaskchallengesstudentstoexploretheideaofmeasurementofdistance.Afterobservingtwostudentsjumpingagivendistance,theclassdiscussestheirobservationsanddetermineswhichstudentjumpedfartherthantheother.Thistaskchallengesstudentstodeterminewhowinsaracebetweentwobrothersjumpingupthestairwaywhereonebrotherjumpsfartherthantheother.Astudenthastoreasonbetweennumberofjumpsandlengthofjumps.

CommonCoreStateStandardsMath-ContentStandardsMeasurementandDataDescribeandcomparemeasurableattributes.K.MD.1Describemeasurableattributesofobjects,suchaslengthorweight.Describeseveralmeasurableattributesofasingleobject.K.MD.2Directlycomparetwoobjectswithameasurableattributeincommon,toseewhichobjecthas“moreof”/“lessof”theattribute,anddescribethedifference.Forexample,directlycomparetheheightsoftwochildrenanddescribeonechildastaller/shorter.Measurelengthsindirectlyandbyiteratinglengthunits.1.MD.2Expressthelengthofanobjectasawholenumberoflengthunits,bylayingmultiplecopiesofashorterobject(thelengthunit)endtoend;understandthatthelengthmeasurementofanobjectisthenumberofsame-sizelengthunitsthatspanitwithnogapsoroverlaps.Limittocontextswheretheobjectbeingmeasuredisspannedbyawholenumberoflengthunitswithnogapsoroverlaps.

CommonCoreStateStandardsMath–StandardsofMathematicalPracticeMP.1Makesenseofproblemsandpersevereinsolvingthem.Mathematicallyproficientstudentsstartbyexplainingtothemselvesthemeaningofaproblemandlookingforentrypointstoitssolution.Theyanalyzegivens,constraints,relationships,andgoals.Theymakeconjecturesabouttheformandmeaningofthesolutionandplanasolutionpathwayratherthansimplyjumpingintoasolutionattempt.Theyconsideranalogousproblems,andtryspecialcasesandsimplerformsoftheoriginalprobleminordertogaininsightintoitssolution.Theymonitorandevaluatetheirprogressandchangecourseifnecessary.Olderstudentsmight,dependingonthecontextoftheproblem,transformalgebraicexpressionsorchangetheviewingwindowontheirgraphingcalculatortogettheinformationtheyneed.Mathematicallyproficientstudentscanexplaincorrespondencesbetweenequations,verbaldescriptions,tables,andgraphsordrawdiagramsofimportantfeaturesandrelationships,graphdata,andsearchforregularityortrends.Youngerstudentsmightrelyonusingconcreteobjectsorpicturestohelpconceptualizeandsolveaproblem.Mathematicallyproficientstudentschecktheiranswerstoproblemsusingadifferentmethod,andtheycontinuallyaskthemselves,“Doesthismakesense?”Theycanunderstandtheapproachesofotherstosolvingcomplexproblemsandidentifycorrespondencesbetweendifferentapproaches.MP.5 Useappropriatetoolsstrategically.Mathematicallyproficientstudentsconsidertheavailabletoolswhensolvingamathematicalproblem.Thesetoolsmightincludepencilandpaper,concretemodels,aruler,aprotractor,acalculator,aspreadsheet,acomputeralgebrasystem,astatisticalpackage,ordynamicgeometrysoftware.Proficientstudentsaresufficientlyfamiliarwithtoolsappropriatefortheirgradeorcoursetomakesounddecisionsaboutwheneachofthesetoolsmightbehelpful,recognizingboththeinsighttobegainedandtheirlimitations.Forexample,mathematicallyproficienthighschoolstudentsanalyzegraphsoffunctionsandsolutionsgeneratedusingagraphingcalculator.Theydetectpossibleerrorsbystrategicallyusingestimationandothermathematicalknowledge.Whenmakingmathematicalmodels,theyknowthattechnologycanenablethemtovisualizetheresultsofvaryingassumptions,exploreconsequences,andcomparepredictionswithdata.Mathematicallyproficientstudentsatvariousgradelevelsareabletoidentifyrelevantexternalmathematicalresources,suchasdigitalcontentlocatedonawebsite,andusethemtoposeorsolveproblems.Theyareabletousetechnologicaltoolstoexploreanddeepentheirunderstandingofconcepts.