SamanthaVollbrecht

FourthGradeGeometryandMeasurement:PerimeterandArea

Objective:

• Studentswillknowtheperimeteristhedistancearoundtheoutsideofapolygon.• Studentswillbeabletofindtheperimeterofpicture‐representedobjects,whichcan

bedividedintorectangularshapes.• Studentswillbeabletofindtheareaofpicture‐representedobjects,whichcanbe

dividedintorectangularshapes.• Studentswillknowareaislabeledinsquareunits.

Standard:

• 4.3.2.4:Findtheareasofgeometricfiguresandreal‐worldobjectsthatcanbedividedintorectangularshapes.Usesquareunitstolabelareameasurements.

Materials:

• LaminatedPictures‐RepresentedObjects• Markers• Perimeter/Areastory• Storyrepresentedshapes• Pencils• Papersquareunits• Perimeter/AreaTable

Motivation:

• GoodMorning______and______howareyoudoingtoday?

o Good,excited,okay

• I’mgladtohearthat!Ihaveanewlessonplannedforustoday,withactivities,butwemustreviewfirst.Whatarethethreetypesofangleswetalkedaboutlastweek?

o Acuteo Obtuseo Right

• Howdoweknowifanangleisacute?

o Thespacebetweenthelinesislessthan90degrees.

• Thatiscorrect,thankyou______.______,howdoweknowisanangleisarightangle?

o Thespacebetweenthelinesisequalto90degrees.

• Yes,arightangleisequalto90degrees.Whataboutanobtuseangle?

o Thespacebetweenthelinesisgreaterthan90degrees.

• Yesthatiscorrect.Thankyouforreviewingangleswithme.Lastweek,wealso

discussedfractionsandequivalentfactions.Whocanremindmewhatequivalentfactionsare?

o Theyarefactionsthatlookdifferent,butareworththesame.

• Thatisright,thankyou_____.Inordertomaketwofactionsequivalent,whatare

magicwordsIhavetosay?

o Ifyoudoittothetop,youdoittothebottom.

• Yes,thankyou,thosearethemagicwords.Wewillreviewmoreduringoutnextmeeting;however,wewillcontinueourlessontodaywithawholenewtopic.Haveyoueverwantedtoknowthedistancearoundsomething?Whatdidyouwanttofindthedistanceof?

(Studentssharereal­lifeorfigurativeexamples.Ifstudentscannotcomeupwithone,giveoneofyourown.Itmayinvolveafence,orthedistancearoundablockonawalk)

• Nicebrainstorming______and_______,thankyou.Haveyoueverwantedtoknowhowmuchspaceanobjecttakesup?Well,today,wewillbelearninghowtodobothofthesethings.First,Iwillbeginourlessonwithastory.ThisstoryisaboutabrotherandasisternamedBenandAmy.BenandAmyhaveaproblem;let’sfigureoutwhatitisandhelpthemsolveit.

Procedure:(Atthistime,readthestoryaboutAmyandBen.Promptstudentstoexplorethepuppykennelproblemwiththestudents.Checkcomprehensionandaskstudentstoanswerthequestionswrittenintothestory.UsetheBluesquaresandpapersquareunitstofindtheperimeterandtheareaofeachofthekenneloptions)

• WhatisBenandAmy’sproblem?

o Theydonotknowhowbigofakenneltobuildtheirnewpuppy

• Howbigwouldyoumakethekennelforthepuppy?

o Bigsotheycanrunaroundandplayo Asbigasmyyard

• Whatistheperimeter?

o Thedistancearound

• HowdoBenandAmyfindtheperimeter?

o Addthesidestogether

• Whatistheperimeterofthefirstkenneldrawing?

o 20units

• WhyisBenconfused?

o Alloftheperimetersare20

• WhatisAmy’ssolution?

o Findtheareaofthekenneldrawings

• Whatisthearea?

o Theamountofspacetheytakeup

• HowcanwefindtheArea?

o Countthesquareunits

• Istheareadifferentforeachkenneldrawing?

o Yes

• Whichkennelwouldyouchoosetobuildforapuppy?

o 1,2or3

• WhichshapedoAmyandBenchoosetouse?

o Thefirstrectangle

• Let’sreviewwhatwehavelearnedfromthestory.Whatistheperimeterofashape?

o Thedistancearound

• Yes,thatiscorrect______,thankyou.______,whatistheareaofashape?

o Thespaceittakesup

• Yes,thankyou.Theareaisthespaceashapetakesup.Howdowefindthearea,whatisitlabeled?

o Findhowmanysquareunitsfitintheshapeo Welabelit“unitssquared”

• Thatiscorrect.Thankyouforyourparticipationandhelp.Wearelearningalotof

importantinformationtoday!Nowwearegoingtopracticefindingtheperimeterandareaofsomeobjects.Ihaveprintedoffsixdifferentpictures.Iwantyoutousemarkerstotracethesquareunitsontothepicture.Onceyouaredone,usetheunitstofindtheperimeterandtheangle.WriteyouranswersontothetableIhavegivenyou.Donotforgettolabelyouranswers!

(Allowstudentsenoughtimetocompletetheactivityandfillinthetablecompletely.Occasionallyaskstudentstoestimatebeforetheybegintracingthesquares)

• Nowthateachofyouhasfinishedfillingoutyourtable,Iwouldlikeyoutocompareyouranswers.Didsomeonehaveadifferentanswer?Howdidyoufindyouranswers?

o Countedthesquareso Addedthesidestogethero Countedallofthesquareunitstofindthearea

• Whichpicturehadthelargestarea?Didithavethelargestperimeter?

o Thefootballfieldo Itdidnothavethelargestperimeter

• Todaywehavelearnedtheperimeteris…

o Thedistancearoundashape

• Howdowefindtheperimeter?

o Addallofthesidestogether

• Yes,veryniceanswer!Whatisthearea?

o Thespaceashapetakesup

• Howdowefindthat?

o Bycountingthesquareunits

Closure:

• Thankyouforyourparticipationtoday,weaccomplishedalotinashorttime.Iwouldlikeeachofyoutoshareonethingyoulearnedtoday.

o Howtofindperimetero Howtofindareao Welabelareainsquareunits

• Thoseareallimportantthings.Thankyou______and______.Youmaynowreturnto

yourseatsforyournextlesson. InformalAssessment:

• Observation/Conversation• Product/Demonstration(picturerepresentation)• Product(perimeter/areachart)

FormalAssessment:

• NoneReferences:

• Storyadaptedfrom:http://www.mathplayground.com/area_perimeter.html

Perimeter Area

ElephantMaze

PlaneMaze

FarmMaze

FootballField

BaseballField

Playground

Perimeter Area

ElephantMaze

PlaneMaze

FarmMaze

FootballField

BaseballField

Playground