introducing the ratio symbol 3 · dora. calculating ratio 1 eva is baking cakes and cookies. for...
TRANSCRIPT
Introducing the ratio symbol
1 Theratiosshowshadedpartstonon-shadedparts.
Matchtheratios,statementsandbarmodels.
2:3 fivetotwo
5:2 threetotwo
2:5 twotothree
3:2 twotofive
2
Whoiscorrect?
Explainyouranswer.
3 Danihassomecounters,cubesandmarbles.
Completethesentences.
Theratioofcounterstomarblesis :
Theratioofmarblestocubesis :
Theratioofcubestocountersis :
Theratioofcounterstocubesis :
Theratioofcounterstocubestomarblesis : :
4 Bretthasdrawnsometrianglesandsquares.
Theratiooftrianglestosquaresis1:3
a) Aretheremoretrianglesormoresquares?
Explainhowyouknow.
b) Bretthasdrawnmorethan10shapes.
DrawwhatBrettmighthavedrawn.
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The ratio of purple to yellow is 5 : 4
It is 4 : 5
Mo Alex
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5 Herearesomerulersandsomepencils.
a) Whatistheratioofpencilstorulers? :
b) Herearesomemorerulersandpencils.
Whoiscorrect?
Explainyouranswer.
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6 Theratioofhorsestochickensinafieldis2:5
Herearethehorses.Drawthechickens.
7 Shadesquaressothattheratioofshadedtonon-shadedsquares
is1:4
a) b) c)
8 Aboxcontainsdark,whiteandmilkchocolates.
38
oftheboxaredarkchocolates.
12
oftheboxaremilkchocolates.
Therestarewhitechocolates.
Whatdoeseachratiorepresent?
a) 1:3
b) 4:1
c) 3:5
The ratio of pencils to rulers is the
same as in part a).
Ron is wrong because there are more pencils
and more rulers.
Ron
Dora
Calculating ratio
1 Evaisbakingcakesandcookies.
Forevery1cake,shewillbake2cookies.
a) IfEvabakes3cakes,howmanycookieswillshebake?
b) IfEvabakes10cookies,howmanycakeswillshebake?
2 Theratioofredtoyellowcountersis2:3
Thereare20countersintotal.
Howmanycountersofeachcolourarethere?
Youcancolourthecounterstohelpyou.
yellow red
3 Tomhas5greencubesforevery3yellowcubes.
Hehas16cubesintotal.
Drawadiagramtorepresentthis.
4 Estherisbuildingatowerofcubes.
Theratioofredtoyellowcubesis3:1
Thetowerhas6yellowcubes.Howmanyredcubesarethere?
5 Nijahplays21gamesofchess.
Forevery2gamesshewins,sheloses5games.
Howmanymoregamesdoesshelosethanwin?
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6 a) Huanismakingadrinkbymixing1partjuicewith5partswater.
Completethetabletoshowtheamountshewouldneedtouse.
Juice Water
1litre 5litres
2litres
4litres
100ml
200ml
300ml
30litres
750ml
b) Huanmakes1litre500mlofdrinkintotal.
Howmuchjuiceandwaterdoesheneedtouse?
juice water
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7 AgroupofstudentsstudyFrenchorGermanintheratio3:7
a) Whichsubjecthasthemoststudents?
b) Drawadiagramtorepresentthis.
c) Thereare80studentsintotal.
HowmanymorestudentsstudyGermanthanFrench?
8 Describeasituationforeachbarmodel.
a) green
blue28
b)
green
blue
28
c) green
blue28
Compareanswerswithapartner.
Whatisthesameandwhatisdifferent?
Using scale factors
1 a)Hereisarectangle.
Drawanotherrectanglewhereeachsideistwiceasbig.
b) Hereisasquare.
Drawanothersquarewhereeachsideis4timesasbig.
2 a) Explainwhatitmeansforashapetobeenlargedbyascale
factorof2
b) Enlargetheshapesbyascalefactorof2
3 Completethesentence.
Ashapeinwhicheachsidehastripledinsizehasbeenenlargedby
ascalefactorof
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A supporting video can be found at https://vimeo.com/432268677
4 Hereisarectangle.
a) Measurethesidelengthsoftherectangleandlabelthemon
thediagram.
b) Enlargetherectanglebyascalefactorof3andlabelthe
sidelengths.
5 Thesidesoftherectangleareincreasedbyascalefactorof2
Whatistheperimeterofthenewshape?
cm
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6 Theshapehasbeenenlargedbyascalefactorof112
Fillinthedimensionsofthenewshape.
7 TriangleAhasbeenenlargedbyascalefactorof5tomaketriangleB.
Findtheperimeterofeachtriangle.
perimeterofA= perimeterofB=
1cm
1cm
15cm
8cm
10cm
cm
cm
cm
14km
A
B75km
Ratio and proportion problems
1 Whitneybuys6cansoflemonadefor£3
a) Howmuchdo12canscost?
b) Howmuchdo3canscost?
c) Howmuchdo15canscost?
2 Theratioofredtogreengrapesinabowlis3:1
a) Explainwhatthismeans.
b) Thereare12moreredgrapesthangreengrapes.
Whatisthetotalnumberofgrapesinthebowl?
3 Amirismakingsomechocolatechipbiscuits.
Hehasthislistofingredientstomake6biscuits.
a) HowmuchofeachingredientdoesAmirneedtomake
2biscuits?
butter g plainflour g
sugar g chocolatechips g
b) HowmuchofeachingredientdoesAmirneedtomake
10biscuits?
butter g plainflour g
sugar g chocolatechips g
c) Amirhas240gofchocolatechips.
Whatisthemaximumnumberofbiscuitshecanmake?
©WhiteRoseMaths2019
£3
Chocolate chip biscuits (makes6)
120gbutter
72gsugar
180gplainflour
60gchocolatechips
A supporting video can be found at https://vimeo.com/432268751
4 Dexterhassome20pand50pcoinsinajar.
Foreverythree20pcoinshehasone50pcoin.
Thereare12coinsinthejarintotal.
Howmuchmoneyisinthejar?
5 Adrinkismadeusing3partsorangejuiceto2partslemonade.
Esthermakes1.2litresofthisdrink.
Howmuchorangejuicedoessheneed?
ml
6 Twoshopssellthesamecerealbutindifferent-sizedboxes.
Shop A
500gofcornflakes
£2.10
Shop B
750gofcornflakes
£3.30
Whichshopisbettervalueformoney? Shop
Explainwhy.
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7 Doradrawstwosimilarrectangles.
Thelengthandwidthofbothrectanglesareevennumbers.
Whatisthelargestpossibleareaforthesmallrectangle?
cm2
8 Aishahastwoboxesofsweets.
• Inthefirstbox,theratioofredsweetstogreensweetsis3:1
• Inthesecondbox,forevery2orangesweetsthereare
3yellowsweets.
• Thereisthesamenumberofsweetsineachbox.
• Thereare12yellowsweetsinthesecondbox.
Howmanysweetsareinthefirstbox?
My larger rectangle is 4 times the size of the
smaller one.
The perimeter of the larger rectangle is 48 cm.