Singapore math gr 3 textbook 3b

PROMARV
MNTHEMATOGS 3B

Primary Mathematics Proiect Team
Project Direcior
Dr Kho Tek Hong
Team Members
Chee Kum Hoong, Heclor
Chip Wd Lung
Liang Hin Hoon
Lim Eng Tann
Lim Hui Cheng, Rosalind
Ng Hwee Wan
Ng Siew Lee

Curriculum Specialists
Cheong Ngan Peng, Christina
Ho Juan Beng

::ll

Curriculum Planning & Development Division
Ministry of Education, Singapore

ffirr"EP,5SA,t
An inorint of fines Media


of Singapore
Curriculum Development

'nslitule
Curriculum Planning & Development
Dlvision
Ministry ol Education, Singapore

@ 1982, 1993
@ 1997,1999

Pub ished by

Times lvledia Privale Limit€d

Anember of the Times Publishing Grcup
Times Cenire
1 New lndust al Road
Singapore 536196
E-mail: lps @ tpl.corn.sg
On ne Book Slore: hltp://www.timesone.com.sg/fpl
First publlshed
Second Edilion
Th rd Ed
Repr

tion
nted

1982
1993
1999
2000, 2001 (lwice)

Al

rig his reserved. No parl ot th s publication may be
reproduced, slored n a retrieva sysiem, ortransmilted,
in any form or by any means, eeclronic, rnechan cal,
p"oLocopy 19. re.o'dirq or orl_prw sF. wrtl oullhF prio'
perm sson of the p!blishers.

tsBN 981 01 8050 0
Prinled in Singapore by C.O.S. Pinterc Pte Ltd

llluslrator
Pau Yong

ACKNOWLEDGEMENTS
The project ieam would like lo record their thanks to the loLlowing:

.
.
.

members of the Primary l\,4alhematics Tearn who developed the iirst edilion and second
edition of the package
members oi the Steering Committee for the second ediuon of the package

teachers who tested the materials in the package and provided useiul jnsights and
suggestions

.

.

Educational Techno ogy Division,
components ol the package

lor the design and production of the audio-visual

all those who have helped in one way or anoiher in the development and production of the

package


PREFACE
The Primory Mothemdtics Pockoge comprises textbooks,
workbooks, teocher's guides ond oudio-visuol moteriols.

The moin feoture of the pockoge is the use of the Concrete Pictoriol + Abstrqct opprooch. The pupils ore provided with the
necessory leorning experiences beginning with the concrete ond
pictoriol stoges, followed by the obstroct stoge to endble them to
leorn mothematics meoningfully. Like the previous editions of the
pockoge, this edition encouroges octive thinking processes,
communicotion of mathemoticol ideos ond problem solvinq.
This textbook is cccomponied by two workbooks ond o teocher's
guide. lt comprises 9 units. Eoch unit is divided into ports: @, @,
. . . Eoch port storts with o meoningful situotion for communicotion
ond is followed by specific leorning tosks numbered 1,2, . . . fhe
srg n

is used to link the textbook to the workbook

exerctSes.

Proctice exercises ore designed to provide the pupils with further
proctice ofter they hove done the relevont workbook exercises.
Review exercises ond revision exercises ore provided for cumulotive
reviews of concepts ond skills. All the proctice exercises. review
exercises cnd revision exercises orp nnlionnl eyer.i
The colour patch I is used to invite active porticipotion from the
pupils ond to focilitote orol discussion. The pupils ore odvised not
to write on the colour potches.


CONTENTS
Mentol Colculotion

1
2
3
4

Additlon
Subtroction
Multiplication
Division

6
8
10

PRACTICE 1A
PRACTICE 1B

12

11

Airport

Length
'l ' Metres ond Centimetres
PRACTICE

2

13

14

24

18

Kilometres

19

PRACTICE 28

23

Weight

'l

Kilogroms ond Croms
PRACTICE

2

24
28
29
33

34

More Word Problems
PRACTICE 38

Review A

34

Review B

35

Cqpocity
Litres ond Millilitres

PRACTICE

44

PRACTICE 48

Review C

@@ffiffi

36
42
43

44


6
8
t0
l1

Grophs
Bor Crophs

45

Froctions
1 Froction of o Whole

fl

PRACTICE

2

t2

t3

64

56
57
62

Equivolent Froctions
PRACTICE 6B

Review D

63

Time
t4
t8
t9

1

Hours ond Minutes
PRACTICE

2

74

Other Units of Time
PRACTICE 78

r3

Review

E

fiffi
n

65
73
74
76

77

Geometry
t8
t9
i3

14

t5

|6
12
L?

t4

1
2

Angles
Right Angles

79
81

Areo ond Perimeter

1
2
3

Areo
Perimeter
Areo of o Rectongle
PRACTICE 9A

Review

F

83
88
92

94
95


Mentol Cqlculqtion

O

Addition
Add 46 ond27.

o

a@w

@

ffi@

awffi

a@@

46

27

a@@

.WW
46+27

207
Add 20 to 46 first.

""m
+O

+2O OO ++7

-------------+

/5

46+27=a

6


1. (o) 23 *'0, I *4, I
23+14=a

s419- I *6, 1

16)

5++36=l
(c) 38 -119,

I *s, I

38+45=l
2. (o) Whot number is 3 more thon 68?
(b) Whot

3.

number is 20 more thon 94?

Add.

(o) 43 + 30

(b)

(s)36+23

(h)27+3s

(d)72+s

20

(e)33+7
67 +

(c)

85 + s0

(f)64+8
(D ss+26

f ilil;ili
4.

Find the sum of 58 ond 16.

58+16=l

s.

Add.

(o)

39 +

27

(b)

sB +

34

(c)

4s + 6s
l-

-",b""k

',.*-

\


@

Subtrqction
Subtroct 34 from 87 .

OW
ow
oaw
oa ww
aa @w
t--Y

a7

,/\

304

]

a7

Subtrqct 30 from 87 first.

-30
6t-5l-..._5J
S7

1.

-4

-34=l

(o) 6s ---l!-

I -', I

O5-12=l
rhr

-34

za -i0 . I

-5. I

t6-46=l
I -t, I
03-28=l

(c) 6: --?9;

8


2. (o) Whot number
(b) Whot

3.

A

tess fnon 5 t(
30 less thon 76?

Subtroct.

(o) 70 - 30
(c) 68 - 60
(e) 83-3

(b) ss -70
(d) s8 -6

(f)

47 _J

(b)
(d)

64
s6
63

Subtroct.

lo) 46 (c\ R7
5.

number

z

52

(f)

47

-34
-55

Find the difference between 90 ond 18.

90-18=l

o.

Subtroct.
/'n\ ?O 2a
(c) 70 65
(e) a0 29

(b) 60 (d) s0 -

- It]
a0@)
(D s0- 39

(f)

(h)

9

80
70

-

s6
17

s8
s8


Multiplicqtion

3 tens x 4=12tens

30x4=I
r. to) rvrurupry b rens oy 5.

6tensx5=ltens

60r5=l

(b) Multiply 4 hundreds by 3.

4 hundreds

;

3=

|

hundreds

400x3=l
2.

Multiply.

(o) 8x7
(d) s0x9

(s)

600 x 3

(b)
(")
(h)

80x7
40x8
300x5

(c)

800 x 7

(f) 90x6
(D 7oox4

f;;.,,*.^*
10

'-

@ Division
\

$
bt

6tens:3=2tens

60*3=l
'1.

(o)

Divide 8 tens by 4.

8tens=4=ltens

80*4=I
fo

(b)

Divide 6 hundreds by 2.

I

6 hundreds = 2 =

!

hundreds

600*2=l
2.

Divide

(o) 9+ 3
(d) 40+2
(9) 320 + 8

(b)

90-3
360-6

(h) 24OO + 4

(c)

(f)

(i)

900 + 3
400 - 10
1oo0

-

lilil;;;
11

5

-\


PRACTICE 1A
Find the volue of eoch of the following:

(o)
1. 65+28
2. 99+99
3. 78-45
4. 99-98
5. 4x30
6. 500 - 5
7. 100x6
8. 160+8
9. 6x100

(b)
34+66
99+98
90-56
83-75
50x8
600: 10
5x90

240-3
40x6

(c)

18+84

27+45

90-85
98-97

200x9
400

_

2

300x7
810+9
500x5

10. (o) Whot number is 29 less thon 84?

(b) Whot number is 68 less thon 310?
(c) Whot number is 35 more thon 475l,
(d) Whot number is 97 more thon 5397?

11. There cre 80 poges in one exercise

book.
How mony poges ore there in 6 exercise books?

12. A shopkeeper pocked 200 onions equolly into 5 bogs.
How mony onions were there in eoch bog?

13. Mr Wu sold 70 buns on Fridoy.
He sold 4 times os mony buns on Sundoy cs on Fridoy.
How mony buns did he sell on Sundcy?
12


PRACTICE 18
Find the volue of eoch of the followinq:

(o)

t.

fu

2. 40
3.6

(b)
3
2

X

90
q

60
80
7

(.)

x5

+4
x

400

+8

30 x6
600 +-3
300 x8
720 +-9

4.

270

5.

Alice soves $50 o month.
How much does she sove in 8 months?

6.

A coke shop sold 200 koyo buns.
It sold 4 times os mony koyo buns os chocolote buns.
How mony chocolote buns did it sell?

320

7. A fruit seller bought 9 boxes of peors.
There were 40 peors in eoch box.
How mony peors did he buy cltogether?

8.

There ore 6 coins in o set.
How mony coins ore there in 200 sets?

9.

Mr Fu pocked 250 tomotoes into pockets of 5 eoch.

(c)
(b)

How mony pockets of tomotoes were there?
He sold oll the tomotoes ot $2 o pccket.
How much money did he receive?

10. (o) Mr Lin bought 98 blue pens ond 62 red pens. How

(b)

mony pens did he buy oltogether?
He divided the pens equolly into 8 boxes. How mony
Dens were there in ecch box?
13


Length

O

Metres ond Centimetres
Cet o metre ruler ond find out how lonq 1 metre

is.

Estimote the length of the cholkboord in the clossroom.
Then check by meosuring it with the metre ruler.

l=lHl=l
riF:?l

ls the length closer

to2mor3rn?

Estimote the height of the door in your clossroom.
Check by meosuring.
ls the door 2 m high?

14


The metre (m) ond centimetre (cm)
ore units of length.

1m=100cm

1.

2.

1m 25 cm.
1m2s cm I cm more thon 1 m.

Ali's height

IS

(c)
(b) 1m2s

cm

1..

(o) Write 2 m in centimetres.

(b)

261 =lcm
Write 300 cm in metres.

3OOcm=lm
3.

Wolk 5 steps.
Mecsure the distonce in metres ond centimetres.
Then write the distance in centimetres.
,,15


4. Hoshim's long jump result is 1 m 45 cm.
Write the distonce in centimetres.

1m45cm-1..

5.

Write in centimetres.

(o) 1m90cm (b) 1 m55cm

(d) 2m89cm (e)

3

m8cm

(c) 2m

(fl

86 cm

am 6cm

6. A cor is 395 cm long.

Write the length in metres qnd centimetres.
/-

I

395cm-lmlcm

\-

7. Write in metres ond centimetres.

cm
(d) 299 cm
(o)

180

(b)
(e)

195 cm
304 cm

^_---*:-----\
JUUcm=Jm

oJ

(c)

(f)

I

262 cm
409 cm

8. The tqble shows the results of the shot put finols.

Arronge the distonces in order. Begin with the shortest.

t;il"k,*;; \


9.

Lily hos o piece of red ribbon 3 m 40 cm long ond o piece of

yellow ribbon 1 m 85 cm long.
(o) Find the totol length of the ribbons.
3m40cm

1m85cm

3m40cm+1m85cm=lmlcm

The totol length of the ribbons is

(b)

How much longer
3m40cm

is

I

m

!

the red ribbon thon the yellow ribbon?

1m85cm

3m40cm_img5cm=lmlcm

l..^- .l ''.,

".

The red ribbon is I
the yellow ribbon.

cm.

o;

"r:++

rn

I

1l

,

;

cm longer thon


PRACTICE 2A

1. Write in centimetres.

(o)

(d)

2.

(b) 1m40cm
4m
3m95cm (e) 4m5cm

(c)

(f)

Write in metres ond centimetres.
(o) 120 cm
(b) 225 cm
(d) 618 cm
(e) 963 cm

m25cm
e m9cm
2

(c) 309 cm
(f) 405 cm

3. Find the missing numbers.

(o)
(b)
(c)

(d)
(e)

(f)
A

1m-65cm-lcm
1m-55cm-lcm
2m- 1m75cm-1..
2m-95cm=lmlcm
3m- 2m92cm-1..
3m40cm-6cm=lmlcm

Add or subtroct in compound units.
(b) 3
(o) 2m75cm +3m
(c) 1m26cm +2m65cm (d) 4
s
(e) 5m85cm
(g) 2m55cm -1m50cm(h) 3

m4cm+65cm
m8cm+1m95cm

(f) m90cm-76cm

-5m

m6cm-2m25cm

5.

Rohim is 1 m 60 cm toll.
Roju is 16 cm shorter thon Rohim.
Whot is Roju' s height?

6.

Mr Chen tied two porcels with these strings.
1m80cm

1m65cm

Whot wos the totcl length of the strings?
18


O

Kilometres
The kilometre (km), metre (m) ond centimetre (cm) ore units
of length.

&=

1km

tm

A bus is obout'10 m long,
The totol length of 100 buses
is obout 1 km.

r-

We meosure long distonces
in kilometres.

19


1.

740

1010 m

m ---- !

Jordine Steps

(o)

The distonce between Sentoso ond Jordine Steps

(b)

The distonce between Mount Fober ond Sentoso

islkmlm.
islkmlm.

23 km

42 km

(c)

The distonce ocross Singopore is obout

fo eoSt.
It is cbout

(b)

f

I

km from west

km from north to south.

The distonce from the Bird Pork to Chongi Airport is
obout
km.

I

20


3.

Sentoso

+.i
=.:.
ti;t:;

I

i

runr

i

Der

i
l

.i
ii
itj'

The totol length of the Monoroil route on Sentoso lslond is
obout 6 km 100 m.

Write the length in metres.

k---aa*;)

4.

The distonce oround o running trqck is 400 m.
Roju ron round the trock 3 times.

Heronlkmlm.
(m

5.

Write in metres.
(o) 1 km 600 m

(d) 3kmSsm

6.

(b) 2km 550 m

3km 20m

(c)

2 km 605 m

(f) 4kmsm

Write in kilometres ond metres.

(o) 1830 m
(d) 30s6 m

(b) 23O4 m
(e) 3040 m

21

(c) 2780 m

(f) 4009

m


2km450m
Army Ccrmp

1km850m
Post Office

Librory

Find the distonce between the ormy comp ond the librory.

2 km 450 m + 1 km 850 m =

|

km

I

m

The distonce between the ormy comp ond the librory is

!kmlm.

'1

km40m

School A

920 m
MRT Stqtion

Which school is neorer to the MRT stotion?
How much neo rer?

1km40m-92Om=lm
School B is

!

m neorer to the MRT stction.

22

School

B


PRACTICE 28

1.

Write in metres.

(o) 3 km
(d) 2km60m

2. Write in kilometres
(c) 1680 m
(d) 30e0 m

3.

(b)
(")

1km450m

3km78m

(c)

(fl

2 km 506 m

akm 9m

ond metres.

(b) 1085 m
(e) 3999 m

(.)

2204 m
(f) 4001 m

Find the missing numbers.

1km-800m=lm
1km-600m=lm
(c) 2km-1km45m=lm
(d) 1km-40m=lm
(o)
(b)

(e) 5km-4km94Om=lm

(f) 2km-275m-lkmlm
4.

.

Add or subtroct in compound units.

(o)
(b)
(c)
(d)
(e)

:e

w

(f)

2km650m+3km
3km460m+50m
3km300m+800m
km700m+1km300m

5km950m-4km

kmS2Om-72Om

(g) 6km25m-3km35Om
(h) 5km40m-3km990m

5.

Find the distonce between the gun boot
ond the Iighthouse.

2 km

940

4km400m
:E&23

?4


Weight
,-,

It

Kilogroms ond Grqms
The kilogrom (kg) ond grom (9) ore units of weight.

lkg=lQggg

The porcel weighs 650 g.

The gropes weigh

ls.

The popoyo weighs

lksIs.