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
