Rounding decimals Use the number line to round these decimal … · 2020-04-20 · Rounding...

Rounding decimals

1 Showthepositionofeachnumberonthenumberline.

Usethenumberlinetoroundthesedecimalstothenearest

wholenumber.

a) 7.2

7.5

7 8

Thenearestwholenumberis

b) 14.8

14.5

14 15

Thenearestwholenumberis

c) 6.5

Thenearestwholenumberis

Explaintoapartnerhowtorounddecimalnumberstothenearest

wholenumber.

2 Usethenumberlinetoroundthesedecimalnumberstothe

nearesttenthandthenearestwholenumber.

a) 7.23

7.25

7.2 7.3

Thenearesttenthis

Thenearestwholenumberis

b) 14.56

14.55

14.5 14.6

Thenearesttenthis

Thenearestwholenumberis

c) 6.45

Thenearesttenthis

Thenearestwholenumberis

Explaintoapartnerhowtorounddecimalnumberstoone

decimalplace.

©WhiteRoseMaths2019

©WhiteRoseMaths2019

3 a) Whenroundingtothenearesttenth,how

manydigitswilltherebeafterthedecimalpoint?

b) Roundeachnumbertoonedecimalplace.

1.33 4.03

1.34 4.04

1.35 4.05

1.36 4.06

1.37 4.07

4 Roundeachnumbertothenearesttenth.

a) 4.21 d)11.86 g) 12.92

b)8.09 e) 5.67 h) 10.65

c) 4.84 f) 0.15

5 Circleeachdecimalthatroundsto6.2

6.32 6.23 6.27 6.17 6.12 6.25

Explainyourreasoning.

6 Herearetheweightsinkilogramsofsomeparcels.

3.48kg 1.42kg 10.65kg 1.03kg

a)Roundtheweightofeachparcelto1decimalplace.

kg

kg

kg

kg

b)The weight of each parcel has been rounded to the nearest 100g.

Isthistrueorfalse?

Talkaboutitwithapartner.

7 Amiristhinkingofanumber.

Roundedtothenearestwholehisnumberis5

Roundedtothenearesttenthhisnumberis4.8

WriteatleastfourdifferentnumbersthatAmircouldbethinkingof.

8 Afarmerisbuildinganewfenceforhersheepfield.

Herearethemeasurements.

Shewantstobuildafencearoundthewholefield.

Estimatehowmuchfencingyouthinkshewillneed.

Talkaboutyourestimatewithapartner.

89.56m

125.45m

Order and compare decimals

1 Whichnumberisgreater?

Tickyouranswer.

T O Tth Hth

1 1 0.1 0.1

0.1

0.01 0.01

0.01 0.01

0.01

T O Tth Hth

1 1 1 1 1 1

0.01 0.01

Explainyouranswer.

2 Whichisthesmallernumber?

Tickyouranswer.

T O Tth Hth

10 1 1 1 1

0.1 0.1

0.1

0.01 0.01

0.01 0.01

0.01

T O Tth Hth

10 1 1

1 1

0.1 0.1

0.1 0.1 0.1 0.1

Explainyouranswer.

3 Useplacevaluecounterstomakeeachofthenumbers.

4.08 5.14.13

a) Whichisthegreatestnumber?

b) Whichisthesmallestnumber?

Howdoyouknow?

4 Herearesomenumbersinaplacevaluechart.

Ones Tenths Hundredths Thousandths

3 2 3 43 1 63 2 0 83 1 4 5

Writethenumbersinorder,startingwiththegreatest.

5 Mo,Amir,Ron,TeddyandJackaremeasuringtheirheightswith

ametrerule.

Writethenamesandheightsofthechildreninorderfromshortest

totallest.

Name Height

©WhiteRoseMaths2019

Mo

1.35m

Amir

1.53m

Ron

1.32m

Teddy

1.3m

Jack

1.5m

©WhiteRoseMaths2019

6 AlexandDoraarecompetinginthelongjump.

Alexjumps1.35metresandDorajumps1.4metres.

a) IsDoracorrect?

Talkaboutitwithapartner.

b) Kimjoinsinthecompetition.

Whatistheshortestdistanceshecanjumptogointothelead?

7 Writethenumbersinascendingorder.

a) 0.45 0.654 0.546 0.405

b) 7.2kg 7.212kg 7.21kg

c) 25.391 25.309 25.093 25.193

8 Dexteristhinkingofanumber.

WhatpossiblenumberscouldDexterbethinkingof?

9 Tickthenumbersthatareequalto2.5

Circlethenumbersthataregreaterthan2.5

Youwillneedtoconvertthemixednumberstodecimal

numbersfirst.

2.05 25

10 212

25

100 2.53 235

2.501 280

100 23

10

It is a decimal number with 2 decimal places that is

greater than 2.47 but less than 2.58

Alex wins because 35 is greater than 4

Understand percentages

1 Completethesentenceforeachdiagram.

a) Thereare partsoutofa

hundredshaded.

Thisis %.

b) Thereare partsoutofa

hundredshaded.

Thisis %.

c) Thereare partsoutofa

hundredshaded.

Thisis %.

2 Completethetable.

Hundredsquare Percentage

82%

3 Shade15%ofthehundredsquarered.

Shade32%ofthehundredsquareblue.

Whatpercentageofthehundredsquareisnotshaded? %

©WhiteRoseMaths2019

©WhiteRoseMaths2019

4 a) Is1%ofthisbarmodelshaded?

1%

Explainyourreasoning.

b) Whatpercentageofeachbarmodelisshaded?

%

%

5 Passengersareboardingaplane.

Theplanehas100seats.

a) 10%oftheseatsarealreadyfull.

Howmanypassengersarealreadyontheplane?

b) 15%oftheseatshavenotbeenbooked.

Howmanyseatshavebeenbooked?

c) Howmanypassengersstillneedtoboardtheplane?

6 Dexterhas£1tospend.

Hebuyssomestickers.

WhatpercentageofhismoneydidDexterspend?

%

7 AishaandBretthavebeensellingticketsfortheschoolplay.

Thereare100seatsavailable.

• OnMondaytheysold34%ofthetickets.

• OnTuesdaytheysold42tickets.

• BytheendofWednesday,95%oftheticketshadbeensold.

HowmanyticketsdidtheysellonWednesday?

OnWednesdaytheysold tickets.

8 Shade85%ofthisbarmodel.

Compareanswerswithapartner.

I got 35p change.

Goo

d Work

Excellent

W

ell Done

VERY G OO

D

GREAT

W

hat a Star

WELL

DONE

Percentages as fractions and decimals

1 Herearefourhundredsquares.

A C

B D

Completethetable.

Hundredsquare

Percentage Fraction Decimal

A52

100

B

C

D

2

Provethat0.2isequalto20%.

Youmayusethehundredsquaretohelpyou.

Whydoyouthinksomepeoplethinkthat0.2isequalto2%?

3 Completethefraction,decimalandpercentageequivalents.

a) 32%=100

=

35%=100

=

48%=100

=

b) 17100

= %=

9100

= %=

90100

= %=

©WhiteRoseMaths2019

c) 0.29= %=100

0.71= %=100

0.03= %=100

©WhiteRoseMaths2019

4 Write<,>or=tocompletethestatements.

a) 50%5

100 d)40

100 40%

b) 25%50100 e)

70100 7%

c) 14%41100 f) 82%

82100

5 Writethevaluesinorderfromsmallesttogreatest.

a) 33%301003%

13100

b) 299%911009%

910

c) 2.52510025025%of100

251000

6 Convertthefractionstohundredths.

Completethedecimalandpercentageequivalents.

a) 150300=

100= = %

b) 25500=

100= = %

c) 48300=

100= = %

d) 1850=

100= = %

e) 1325=

100= = %

7 Circleallthefractionsthataregreaterthanorequalto50%.

1050

45

50100

3080

150

70140

8 JackandDoragoshoppingwiththesameamountofmoney.

Jackspends13ofhismoney.

Doraspends30%ofhermoney.

a) Whospendsmoremoney?

Usefractionandpercentageequivalencetoexplain

youranswer.

b) JackandDoraeachstartedwith£300

Howmuchmoneydotheyeachhaveleft?

Jack Dora

Equivalent F.D.P

1 Rosiemakesanumberona100beadstring.

a) Whatfractionofthebeadstringiscircled?

b) Writethefractionasadecimal.

c) Writethedecimalasapercentage.

%

2 Circlethevalueoneach100beadstring.

a) 70%

b) 0.08

c) 45100

d) 95%

3 a) Whatfraction,decimalandpercentageofthehundredsquare

isshaded?

Hundredsquare Fraction Decimal Percentage

Compareanswerswithapartner.

Didyougetthesameanswers?

Didyousimplifyanyofyouranswers?

b) Completethetable.

Quarters Hundredths Decimal

14 100

4

50100

0.75

©WhiteRoseMaths2019

©WhiteRoseMaths2019

4 Usethediagramtohelpyoucompletetheequivalencestatements.

100%

50% 50%

20% 20% 20% 20% 20%

10% 10% 10% 10% 10% 10% 10% 10% 10% 10%

a) 1whole= % c) 110

= = %

12

= % 310

= = %

15

= % 710

= = %

110

= % 910

= = %

b) 15

= = %

25

= = %

35

= = %

45

= = %

55

= = %

5 Filipgetssomemoneyforhisbirthday.

Hespends25

ofhismoneyandsavestherest.

Whatpercentagedoeshesave? %

6 Doraisdoingaschoolsurvey.

ShecompareshowmanychildrenwearglassesinClass4and

Class5

• 15

ofthechildreninClass4wearglasses.

• 25%ofthechildreninClass5wearglasses.

• Bothclasseshavethesamenumberofchildren.

Whichclasshasmorechildrenwhowearglasses?

Explainyourreasoning.

7 Thereare30childreninClass5

• 25

havebrownhair.

• 50%haveblondehair.

a) Whatpercentageofchildrendonothavebrownorblondehair?

%

b) Whatinformationdidyounotneedtoknowtoworkout

theanswer?

8 14

=25%= 25100

= 2501000

Usethisfacttoconvert18

and38

todecimals.

18

= 38

=