DIGITAL TEXT BOOK DUAL LANGUAGE MATHS YEAR 4 MIKE POJAN 2020

1 Total up the value of money. Specimen

Specimen

RM10000 RM10000 RM10000

Specimen Specimen Specimen

RM150 RM6 RM1000

2 Round off the following values of money to the nearest ringgit.

a RM4 786.65 b RM64 093.40 c RM90 999.50

3 State 3 values of money when rounded off to the nearest ringgit
become:

a RM400 b RM7 653 c RM71042 4

Add RM14631.25, RM7419.20 and RM10291.15.

5 Calculate.

a RM92 950 + RM7005 – RM4 000 =

b RM82 004 – RM53 760 + RM9112=

c dRMe71439.05 – = RM56372.50

RM850 ÷ = RM0.85

÷ 1000 = RM12.50 Bil Total

6 Solve. Electric RM75.20

a. The table shows the total bill that Water RM21.80

Encik Hashim has to pay. He pays with Telephone RM84.70

an amount of RM200. Calculate his balance.

b. Puan Nyonya wants to buy 2 washing
machines and 3 refrigerators for her new
restaurants. Puan Nyonya pays with 104
pieces of RM50notes. Calculate her balance. RM715.90 RM1243.75

TEACHER’S 143
NOTES

7 State the currency and country for the following notes.

a Specimen b Specimen c Specimen

d Specimen e Specimen f Specimen

8 Name the country that uses the following currencies.

a Pound Sterling b Won c Renminbi

d Naira e Rupiah f Riel
g Baht h Kyat i Peso

9 Which payment instrument is suitable to use for each situation?

Daily situations Payment
instrument
Buying fish and vegetables at the market.
Using card to call a friend.
Buying airline ticket to go on a tour.
Giving donation to fire victims.
Buying electrical items at a supermarket.

TEACHER’S
NOTES

11444

11 School
TIME
The earth rotates
Recognise time on its axis in 1day.

Day and hour
1

Sundial Water Clock

Hourglass Analogue Yes, the complete
Clock rotation takes
24 hours.
Ancient people used
various instruments to
determine the time.

1day = 24hours

Day and night---------------------------------------------------- Direction of 2 days is equal to how many
Sun rays rotation hours?

 Day 2 days = hours

Night 2 days = 24 hours + 24hours
= 48 hours

2 days = 48 hours

Axis

11.1(i) TEACHER’S Infuse the elements of EMKin exploring the history of time. 145
a NOTES
http://www.bgfl.org/bgfl/custom/resources_ftp/client_ftp/ks2/maths/time/
index.htm.

2 In a year, the Rafflesia blooms for 3
to 5 days only. State 3 days in hours.

3 days = hours

24 hours 24 hours 24 hours

0 12 3

1 How many hours
in 5 days?
24 hours
×3

72 hours

3 days = 72 hours

3 96 hours = days

96 ÷ 24 = days

4 x 24
24 96 day hour

– 96 ÷ 24
0
INFORMATION
96 hours = 4 days

4 6 days 7 hours = hours • Convert 6 days to hours.

6 days 7 hours = 6 days + 7 hours 6 × 24 hours = 144hours
= 144 hours + 7 hours

= 151hours

6 days 7 hours = 151 hours How many days and hours in
100 hours? Explain.

TEACHER’S Relate days and hours based on the situation given.
NOTES
11.1(i)
146 a

Week and day

1 The Patriotic Month is celebrated for 4 weeks.
How many days are there in 4 weeks?

31

4 weeks = days

4 × 7 days = days Remember the
4 × 7 = 28 7 times table.

National Day

4 weeks = 28 days
There are 28 days in 4 weeks.

2 Aisyah and her family went for a holiday in a village for 41days.
How many weeks and days were they there?

41 days = weeks days ×7
41 days = 5 weeks
5 week day
7 41
÷7
– 35
6 INFORMATION

6 days

They were in the village for 5 weeks 6 days.

In the life cycle process of a butterfly, takes about

10 days to transform into . State the time in

weeks and days.

Source: http://www.butterfly-insect.com/diy.book.php

11.1(i) b TEACHER’S Relate weeks and days based on the life cycle of insects such as the cockroach, the 147
NOTES fly and others.

http://www.bgfl.org/bgfl/custom/resources_ftp/client_ftp/ks2/maths/time/
index.htm

Year and month Father Mother
45 years 6 months 42 years
1 Study Kak Ngah’s family chart.
How old is Usu in months?

5 years = months

12 Kak Long Kak Ngah Abang Chik Usu
×5 15years 10 years 8 years 5 years
7 months 5 months 3 months
60
Whose age is the same
5 years = 60 months as 504 months? Explain.
Usu’s age in months is 60 months.

2 187 months = years months

15 × 12
1218 7 year month
– 12
÷ 12
67

– 60
7

185 months = 15 years 7 months INFORMATION

Time taken by planets to make one
complete rotation around the sun.

Jupiter 12 years

Uranus 7 times the time taken by Jupiter

State the time, in months, taken by Uranus.

148 11.1(i) c TEACHER’S Source: http://www.thestar.com.my./20130401/world/ploto-is-a-
NOTES planet-again.asp

Emphasise that leap year and normal year have the same number of months, but
different number of days.
Guide pupils to identify the leap years.

http://www.sheppardsoftware.com/mathgames/time/TimeConversions.htm

Players 4 persons Materials 21pieces of time cards

(10pairs of cards, 1piece of storkcard)

Steps 3
1 Distribute 21pieces of cards to all players.

2 Determine the players turn. The player with the most

cards gets the first turn.

3 Pull out a card from each player according to turns. 4
4 If there are matching cards, the 2 cards are taken out.

5 Repeat steps 3 to 4 until all matching cards are taken

out.

6 The player who gets the stork card wins the game.

1 Convert.

a 9 days = c hours b 8 days 5 hours = hours

37 hours = days hours d 6 weeks = days

e 2 weeks 4 days = days f 84 days = weeks

g 10years 3 months= months h 9 years = months

i How many hours in 7 days? j State 14months in years
and months.

2 How many weeks and days are
there in May 2014?

3 The first Prime Minister of Malaysia, the late Tunku Abdul
Rahman Putra Al-Haj served for about 13 years.
State his term of service in months.

11.1(i) TEACHER’S Prepare a few sets of time cards for enrichment activity.
a,b,c NOTES Game like “Happy Family” is encouraged.

149

Addition of time

1 a The picture shows the handicraft

products of the disabled. Find the 1day 8 hours

total time taken to finish the 1day 9hours

baskets and shell crafts.

1 day 9 hours + 1 day 8 hours =

days hours

day hour 2 days 16hours
19

+1 8
2 17

1 day 9 hours + 1 day 8 hours = 2 days 17 hours

The total time taken to finish the baskets and shell crafts is
2 days 17 hours.

b How many hours does it take to finish all the handicraft
products above?

1 day 9 hours + 1 day 8 hours + 2 days 16 hours = hours

day hour 4 days = 4 x 24 hours
= 96 hours
1 2
1 4 days 33 hours = 96 hours + 33 hours
+2 9 = 129 hours
4 8

16

33

1 day 9 hours + 1 day 8 hours + 2 days 16 hours = 129 hours

The time taken to finish all the handicraft products above
is 129 hours.

150 11.2(i)a TEACHER’S Use time line for addition operation.
NOTES Emphasise the conversion of units from hour to day.

2

Pulau Redang Belum Rainforest 6 FRIM
4 weeks 2 days weeks 1day 1week 5 days

The photography association shot films at the locations above.

a Calculate the time taken for shooting films at Pulau Redang
and Belum Rainforest.

4 weeks 2 days + 6 weeks 1 day = weeks days
week day

4 2
+6 1
3
10

4 weeks 2 days + 6 weeks 1 day = 10 weeks 3 days

The time taken for shooting films at Pulau Redang and Belum
Rainforest is 10 weeks 3 days.

b Calculate the duration taken for filming at the three locations.
4 weeks 2 days + 6 weeks 1 day + 1 week 5 days

= weeks days

week day

42 11weeks 8 days
61

+1 5 +1 –7

11 8 12 weeks 1day

4 weeks 2 days + 6 weeks 1 day + 1 week 5 days
= 12 weeks 1 day
The duration taken at the three locations is 12 weeks 1 day.

State 2 locations which take 42 days for filming.

11.2(i)b TEACHER’S Emphasise the conversion of units from day to week. 151
NOTES Encourage pupils to talk about their school activities in weeks and days like
Reading Campaign and sports practice.

3 Calculate the duration of service for Service Record

Cikgu Sarah at the three schoolsbased Name Duration
on the service record. of school

4 years 9 months + 3 years SKBaiduri 4 years 9 months

8 months + 10 years 4 months SKAngkasa 3 years 8 months

= years months SKAman 10years 4months

year month

4 2
3
+ 10 9 21months ÷ 12= 1year 9 months
17 8

4 17years 21months = 17years + 1year + 9 months
21 = 18years 9months

4 years 9 months + 3 years 8 months
+ 10 years 4 months = 18 years 9 months

The duration of service for Cikgu Sarah at the three schools is
18 years 9 months.

Interview a few teachers at your school. Record their durations of service at
your school and others. Create an appreciation card for their contributions
and state the durations of service at your school.

1 Add.

a. 3 days 7 hours + 2 days 6 hours = days hours

b.12years 1month + 8 years + 20 months = c months

d 9 weeks 3 days + 5 weeks 6 days = weeks days

5 days 8 hours + 4 days 10hours + 12hours = hours

2 Find the total of 40 weeks 2 days, 15days and 8 weeks 4 days.
Give answer in weeks.

TEACHER’S Diversify questions using a calendar.
NOTES
11.2(i)
152 a, b, c

Subtraction of time 4 days 17hours

1

3 days 12hours

Calculate the difference in time taken by the rabbit and the
tortoise to reach Sang Kancil’s house.

4 days 17 hours – 3 days 12 hours = days hours

day hour

4 17
–3 12

1 5

4 days 17 hours – 3 days 12 hours = 1 day 5 hours

The difference in time taken by the rabbit and the tortoise to reach
Sang Kancil’s house is 1 day 5 hours.

2 5 days 5 hours – 2 days 9 hours – 14 hours = days hours

day hour day hour • 9 hours can be subtracted
from 5 hours.
4 29 2 110
– • Convert 1day to 24 hours.
5 5 20 24 hours + 5 hours = 29 hours
–2 9 2 14

2 20 6

5 days 5 hours – 2 days 9 hours – 14 hours = 2 days 6 hours

Add 2 days 9 hours and 14hours. Then, subtract the sum from
5 days 5 hours. Is the answer the same?Explain.

11.3(i)a TEACHER’S Find the difference by doing simulation activities. Do subtraction 153
NOTES by counting down.

http://www.bgfl.org/bgfl/custom/resources_ftp/client_ftp/ks2/
maths/timetables/index.htm

3 What is the difference, in weeks and Mural A
days to complete mural A and mural B? 2 weeks 6 days

2 weeks 6 days – 1 week 5 days
= weeks days

week day

2 6 Mural B
–1 5 1week 5 days

1 1

2 weeks 6 days – 1 week 5 days = 1 week 1 day
Thedifference in time to complete mural A and mural Bis 1 week 1 day.

Solve by changing the unit from week to day first. Is the
answerthe same?

4 19 weeks – 4 weeks 3 days – 6 days = weeks days

week day week day

18 7 13 11

19 0/ 14 4/
–4 6
3–
14
4 13 5

19 weeks – 4 weeks 3 days – 6 days = 13 weeks 5 days

Assume 1month = 4 weeks.
Calculate the time difference in
days for the growth of this chick.

3 weeks 3 months

TEACHER’S Do subtraction by counting down.
NOTES
11.3(i)
154 b

5 Find the difference of life span 45 years
between the orang-utan and the 30 years
panda. Give answer in months. 2 months months 3 months

45 years 3 months – 30 years 2 months =

year month 15years 1month = 180 months + 1month
45 3 = 181months
– 30 2

15 1

45 years 3 months – 30 years 2 months = 181 months
Thedifference of life span is 181 months.

6 14 years 7 months – 8 months – 2 years 3 months

= years months 11 16

14 years 7months 12 years 4 months
– 2 years 3months – 8 months

12 years 4 months 11years 8 months

14 years 7 months – 8 months – 2 years 3 months

= 11 years 8 months

1 Subtract.

a. 8 days 3 hours – 5 days 2 hours = days hours

b. 24 days 7 hours – 10days 15hours – 3 days 9 hours

= days hours

c. 16weeks 2 days – 6 weeks 5 days – 8 days= weeks days
months
d. 31years – 12years 8 months – 5 months= years

2 Solve.
a. Find the difference between 21weeks 4 days and 13weeks 3days.
Give answer in days.
b. How many months more is 50 years than 23 years 9 months?

TEACHER’S Carry out activities to find difference in age amongst friends and relatives.
NOTES
11.3(i)c 155

Multiplication of time

1 How much time, in days and hours, This wood carving
is taken by Raden to do 5 similar is done in 1day
wood carvings? 3 hours.

5 × 1 day 3 hours = days hours

day 1 hour 3

× 5
5 15

5 × 1 day 3 hours = 5 days 15 hours
Time taken to do 5 similar wood carvings is 5 days 15hours.

Estimate the number of wood carvings that can be
done in 11days. Discuss.

2 a Shah Indra attended computer courses.
What is the total time of the two courses?
Give answer in days.

2 × 2 weeks 4 days = days

2 weeks 4 days = 14days + 4 days
= 18days

1

18 days
×2

3 6 days

2 × 2 weeks 4 days = 36 days 2 weeks 4 days

The total time of the two courses is 36
days.

11.4(i) TEACHER’S Do multiplication using different suitable methods, like repeated addition.
a, b NOTES Use schedules for school holidays and co-curriculum activities involving
multiplication of time.
156

b I attended the thirdcourse

for the same duration.

Calculate the duration of
the three courses. State the
answer in weeks and days.

3 × 2 weeks 4 days = weeks days

2 weeks 4 days 12days = 7 days + 5 days
× 3 = 1 week + 5 days
12
6 –7
+1 5 days

7 weeks

3 × 2 weeks 4 days= 7 weeks 5 days
The duration of the three courses is 7 weeks 5 days.

3 4 × 10 years 7 months= years months
7
year month 10
×4

40 28

40 years 28 months = 40 years + 24 months +4 months
= 40 years + 2 years + 4 months
= 42 years + 4 months

4 × 10 years 7 months = 42 years 4 months

TEACHER’S Guide pupils to build conversion of units chart.
NOTES
11.4(i) 157
b, c

Players 4 to 6 persons. 1.FQ2iw.n32uTdi1.eoth3hyafsee2×ttphidaop1aeirf0unsifretp.yCoorieltesfayaapneirlrusdcsaap3e4grimlssiemn.ooaonfgtnhetsh.s
=
Materials Pupil’s register book, question cards.

Steps

1 Teacher retrieves information about pupil’s age
from the register book and give the data to pupils.

2 Distribute question cards to each group.
3 Pupils answer the questions in the allocated time.
4 The group that answers all the questions correctly

in the shortest time wins the game.
5 The group that makes mistakes needs to make

corrections.

1 Multiply. days hours
a. 7 × 8 days 2 hours = years days
b. 6 × 6 years 4 months =
c. 3 × 9 weeks 5 days = weeks months
d. 8 × 3 days 4 hours= hours
e. 4 × 5 weeks 3 days = days
f. 5 × 4 years 7 months =
years

2 Solve.
a. Multiply 6 by 4 days 8 hours. Give answer in days.

b. 9 × 8 weeks 4 days = days Show the

simplest method.
c. Calculate the product for 8 and 10years 9 months.

11.3(i)c TEACHER’S Relate multiplication of time in everyday life.
NOTES Inculcate moral values such as valueing time during group activity.
158 11.4(i)
a,b, c

Division of time Quantity Type of house Duration of

1 a Based on the table, how long completion

does it take to complete a mode3l units Single-storey 6 days 15hours

of a single-storey house? 4 units Double-storey 9 days 4 hours

6 days 15 hours ÷ 3 = days

hours

2 days 5 hours Welcome
3 6 days 15 hours

– 6 – 15

00

6 days 15 hours ÷ 3 = 2 days 5 hours

The time taken to complete the model of a single-storey house is
2 days 5 hours.

b Calculate the time taken to complete a model of a double-storey
house. State the answer in hours.

9 days 4 hours ÷ 4 = hours

2 days 7 hours
4 9 days 4 hours

–8 + 24 2 days 7 hours = 24 hours + 24 hours + 7 hours
1 28 = 48 hours + 7hours
= 55 hours
– 28
0

9 days 4 hours ÷ 4 = 55 hours

The time taken to complete a model of a double-storey house is
55 hours.

5 workers can paint a house in 10hours. Can a worker paint the
house in 2 hours? Discuss.

TEACHER’S Guide pupils to divide units of time by subtracting consecutively.
NOTES
11.5(i)a 159

2 14 weeks 4 days ÷ 6 = weeks days

2 weeks 3 days Convert the remainder
6 14 weeks 4 days 2 weeks to 14days.

– 12 + 14
2 18

– 18
0

14 weeks 4 days ÷ 6 = 2 weeks 3 days

3 12 years ÷ 9 = months

1year 4 months

9 12 years 0 months

–9 + 36

3 36 1year 4 months = 12months + 4 months
– 36 = 16months

0

12 years ÷ 9 = 16 months

1 Divide. b 8 9 weeks 1day
a 2 18days 20hours

c 4 13years 8 months d 5 22 days 7 hours

e. 20 weeks 4 days ÷ 6= weeks days
f. 45 days 12hours ÷ 7 = days hours

2 Divide 30 years 9 months by 9. Give answer in months.

TEACHER’S Expose various calculation and conversion of units strategies to pupils.
NOTES
11.5(i)
160 b, c

Solve the problems

1 The table below shows the duration of operation times for two
multipurpose shops. Find the difference in time the two shops operate.

Multipurpose shop Duration of operation
Era Whole day
Kota 8 hours

Given Duration of operation of Era is whole day or 1day.
Find Duration of operation of Kota is 8 hours.

Difference in time

Operation Subtraction

Solve 1day – 8 hours = hours

1day = 24hours hours

24 hours – 8 hours=

114

2 4 hours

– 8 hours
16 hours

Check 16hours + 8 hours = 24 hours

1day – 8 hours = 16 hours

The difference in time the two shops operate is 16 hours.

If another multipurpose shop operates 2 hours more
than Kota, calculate the duration the shop operates.

TEACHER’S Solve daily problems by drawing diagrams or making tables.
NOTES
11.6(i) 161

2 In a year, a book exhibition is held in 3 stages. Each stage is held for
1week 4 days. Calculate the total time for the 3 stages of the exhibition.

1week 4 days 1week 4 days 1week 4 days
Total

3 × 1week 4 days = weeks days

1 week 4 days Check.
× 3
12 1week 4 days = 11days
3 –7
+1 5 days 1 1 days 4
×3 7 33
4 weeks –28
3 3 days
5

3 × 1week 4 days = 4 weeks 5 days
The total time for the 3 stages of the exhibition is 4 weeks 5 days.

3 Four similar phases of housing projects should be completed
in 9 years. Calculate the time in years and months to complete
one phase.

9 years ÷ 4 = years months

2 years 3 months 9 years
4 9 years 0 months
Phase 1 Phase 2 Phase 3 Phase 4
–8 +12
1 12 ?
– 12
0 How do you check the answer?
Explain.

9 years ÷ 4 = 2 years 3 months

The time taken to complete one phase is 2 years 3 months.

TEACHER’S Underline the key information before solving the problem.
NOTES
162 11.6(i)

A

Solve. 2 days 9 hours B
a How much time boat A
1day 3 hours
sails more than boat Bas
given in the information?

b. A group of pupils made a study about the school history
for 3 weeks 4 days. The folio study was completed in
1week 5 days. Find the total time taken by them.

c. The table shows the duration of timPerotjaekcetn by Fong to Duration
finish three projects. Find the total SHinticimsiedteonarcnyyeseeadneddhtooufrinsi.sh
all the projects. Give your answer 10 hours
9 hours
d. The life span of a jungle cat is abouEtn5glyisehars. While the 7 hours
life span of a tiger is 3 times a jungle cat. Calculate the

life span, in months, of the tiger.

e. The table below shows the age of two pupils.

Pupil Age
Alia 13years 6 months
Danisha 7 months younger than Alia

How old is Danisha?

f Kim attended a course in Putrajaya for 24 days. Calculate
the duration of the course in weeks and days.

g The poster shows the sale of children᾽s GRAND PROMOTION
clothings. The sale is held for 1week 2 days.
The promotion is extended for 9 more days CHILDREN’S CLOTHINGS
because of good response. Calculate the time, 18 July – 26 July 2014
in weeks and days, the promotion is held. Bukit Jalil Stadium

TEACHER’S 11633
NOTES

1 Convert.

a 7 days = hours b 144 hours = days

c 8 weeks 3 days = days d days = 17weeks

e f12years = months

92 months = years months

2 Solve.

a 3 days 8 hours + 15 hours = days hours

b 10years 8 months – 2 years 9 months – 3 years 7 months

= years months

c 6 × 4 weeks 6 days = weeks days

d 11days 6 hours ÷ 5= days hours

3 Solve.
a. Change 8 days 10hours to hours.

b. 16 weeks = days Which is the correct conversion of unit?
16 × 7 days or 16× 10days

c. Multiply 4 by 7 weeks 2 days.
d. 28 years divided by 8. State the answer in months.

4 Solve the following problems.
a. A writer takes 1year 2 months to complete a novel.
A collection of short stories is completed 4 months earlier
compared to the novel. How long does it take to
complete the collection of short stories?

b. Nuriz did a scrapbook in 3 weeks 1day. While Aziah took
half the time taken by Nuriz. Calculate the time taken by
Aziah, in days.

c. Mala is 8 years 9 months. The difference in age between
Mala and her brother, Bala is 2 years 5 months.
Calculate Bala᾽s age.

TEACHER’S
NOTES

1164

12 School
LENGTH

Recognise units of length

1 The length of the pencil 5 mm 0.5 mm

lead is 75 millimetres. Millimetre is used to state
the length of small and short
247pe5ncmil lemad objects. The symbol is mm.

Long

2

The distance from
Merdeka Square to
Petronas Twin Towers
KLCCis 3.5 kilometres.

Kilometre is used to state the
distance between two places.
The symbol is km.

What unit will you use to state:
(i) the thickness of a textbook?
(ii) the distance between Kota Bharu, Kelantan and Kangar,

Perlis? Explain.

12.1(i) TEACHER’S Encourage pupils to explore the usage of mm and km in every day life. 165
a, b NOTES Use search engines and type the key word “location map” to retrieve various
information related to distance in kilometres.

Relationship between centimetres and millimetres

The length of the blue 1cm
line is 1cm or 10 mm.
cm
× 10
0 12 3 4 5 cm mm
0 mm 10 20 30 40 50
÷ 10

10mm 1 cm = 10 mm INFORMATION

1 6 cm = mm 2 120 mm = cm
120 mm = (120 ÷ 10)cm
6 cm = 6 × 10 mm = 12cm
120 mm = 12 cm
= 60 mm

6 cm = 60 mm

3 3 cm 7 mm = mm 4 83 mm = cm mm

3 cm7mm = 30mm + 7mm 83 mm = 80 mm + 3 mm

= 37 mm = 8 cm + 3mm

= 8 cm 3 mm

3 cm 7 mm = 37 mm 83 mm = 8 cm 3 mm

Is 120 mm longer than 19cm? Discuss.

Complete the following. b 631 mm = 63 cm mm
a 152 mm = cm 2 mm d 71 mm = cm mm
c 4 cm mm = 49 mm f 34 mm = 3 cm mm
e cm 9 mm = 909mm

TEACHER’S http://www.ixl.com.math/grade-3/compare-and-convert-metric-units-of-length
NOTES
12.1(ii)
166 a

Relationship between kilometres and metres

Saiful will run 100 m back So, Saiful will run a × 1 000
and forth 5 times for distance of 1000 m. This km m
training today. distance is equal to 1km. ÷ 1000

0 metre 100 metres

INFORMATION

1 km = 1 000 m

1 8 km = m 2 16 000 m = km

8 km = 8 × 1000 m 16000 m = (16000 ÷ 1000) km

= 8 000 m = 16km

8 km = 8 000 m 16 000 m = 16 km

3 71km900 m = m 4 25 300 m = km m

71km 900 m = 71000 m + 900 m 25 300 m = 25 000 m + 300 m

= 71900 m = 25 km + 300 m

= 25 km 300 m

71km 900 m = 71 900 m 25 300 m = 25 km 300 m

5 km 25 m equals to 5 250 m. Explain.

Complete the following.

a 12 km= mm b 78 000 m = km
c 3 km = m = 8 407m
e 8 km d 90 km = f m

50 km m = 50 021m

12.1(ii) TEACHER’S Carry out activities at the school track or field for simulation distance of 1000 m or 167
b NOTES 1km to reinforce pupils’ understanding.

http://www.math- Grills.com/measurement/matric_meters_kilometers_001.html

Measure length of objects good
luck
30 mm
Start measuring from 0 mm. The length of the
Read the measurement at ERASER eraser is 30 mm.
the other end.

DICTIONARY

The thickness of the dictionary is . The width of the bookmark is .

Y
X

Z

mm

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150

1 What is the length of necklaces X, Yand Z?
2 Which necklace is the longest and which is the shortest?
3 What is your conclusion about the length of necklaces X and Y?Explain.

1 State the length of each object. (ii)
ab (i)

i mm ii mm
mm

168 12.2 (i) TEACHER’S Carry out activities to estimate lengths of objects in mm and measure actual
NOTES lengths using measuring tape, thread, paper strip and ruler. Record the
measurements in a table.

http://www.vendian.org/mncharity/dir3/paper_rulers/

Estimate distance The estimated
distance from
Chalet jetty to chalet is
about 1km.
Jet yt 1km
Jetty Health
Centre

Robotic X
Museum
Amusements
Centre

1 What is the estimated distance The estimated

from the chalet to the health centre? distance is 2 times

Jetty 1km Chalet more than 1km.

Chalet Health Centre

Estimated distance = 2 km

Theestimated distance from the chalet to the health centre is about 2 km .

2 State the place that is located almost 4 km from X. Thehealth
centre is located almost 4 km fromX.

3 What is the estimated distance from the jetty to the amusement centre?

Jetty Chalet Amusement centre

Estimated distance = 5 km 1km

5 km

Theestimated distance from the jetty to the amusement centre is about 5 km .

A digital library will be built within 3 km from the jetty. Where is the
suitable location? Explain.

12.2 (ii) TEACHER’S Create more questions on estimation of distances based on the above map.
NOTES Discuss the importance of estimation in daily life.

169

You and three friends found a treasure map X
showing a treasure placed at X . Theestimated
distance from the arrow to the cactus A
area is 1km. Complete the table below to
estimate the distance that you will pass B
through. C

1km

Route A B C Use thread to

Estimated measure the curved
distance route. Compare with
the given estimated
(km)
distance of 1km.

Discuss the route that you have chosen and give reasons.

The diagram below shows the estimated distances from Nelly’s house

to a few surrounding places. Li br ary

Library

Nelly’s

House 1km School

Bus Station Bus Station Internet

Centre

a. Choose the correct answer.

i. The distance from Nelly’s house to the school passing through

the library is (more than, less than) 10 km.

ii. Nelly wants to go to the library, the distance is (more than,

less than) 5 km.

b. What is the estimated distance from Nelly’s house to the Internet

Centre? Discuss and give reasons for your answer.

170 12.2 (ii) TEACHER’S Guide pupils to determine the estimated distances between two places based on
NOTES a given reference.

Addition of length After
3 days
1 Based on the picture, what is the
height of the seedling after 3 days?

5 mm Increased by
2 cm 3 mm
5 mm + 2 cm 3 mm = cm mm

cm mm
5

+2 3

28

5 mm + 2 cm 3 mm = 2 cm 8 mm
The height of the seedling after 3 days is 2 cm 8 mm.

2 Add 32 cm 5 mm and 40 cm 9 mm.

32 cm 5 mm + 40 cm 9 mm = cm mm

cm mm

32 5
+ 40 9

14

Convert 14mm to
1cm 4 mm.

cm mm

1

32 5
+ 40 9

73 4

32 cm 5 mm + 40 cm 9 mm = 73 cm 4 mm

12.3 (i) TEACHER’S http://www.k5learning.com/free-math-worksheets/fourth-grade-4/measurement
a NOTES 171

3 Calculate, in mm the total length of the ropes P, Qand Rbelow.

P 18 cm 2mm
Q 16 cm 5mm

R17cm 8 mm

18 cm 2 mm + 16 cm 5 mm + 17 cm 8 mm = mm

cm mm cm mm

18 2 21
16 5
+ 17 8 18 2
16 5
15 + 17 8

52 5

52 cm 5 mm = 520 mm + 5 mm
= 525 mm

18 cm 2 mm + 16 cm 5 mm + 17 cm 8 mm = 525 mm

The total length of the ropes P, Qand Ris 525 mm.

4 Day Distance of cycle
First 76 km 433 m

Second 10km 662 m

Calculate the total distance in the
cycling competition for the two days.

76 km 433 m + 10 km 662 m = km m

km m km m

76 4 33 1
+ 10 6 6 2
76 433
1095 + 10 6 62

87 095

76 km 433 m + 10 km 662 m = 87 km 95 m

The total distance in the cycling competition is 87 km 95 m.

TEACHER’S Drill pupils on conversion of units using flash cards.
NOTES
12.3 (i)
172 a, b

5 Add 8 km 240 m, 20 km 790 m and 5 km 125m.
Give the answer in m.

8 km 240 m + 20 km 790 m + 5 km 125 m = m

km m km m

1 11 1

8 240 8 240
20 790 20 790
+ 5 12 5 + 5 12 5

1 15 5 3 4 15 5

34 km 155 m = 34 000 m + 155m
= 34 155 m

8 km 240 m + 20 km 790 m + 5 km 125 m = 34 155 m

1 Calculat b km m c cm mm d km m

e. a mm 14 261 51 8 3 128
+ 82 972 10 3 11 492
cm + 41 7 + 7 101
34 7

+ 22 9

2 Aa.dd1.2 cm 3 mm + 4mm = cm mm m
b.15cm 4 mm + 7 mm + 21cm 9 mm = c cm
d 65 km 28 m + 12 km 903m = km m
25 km 114m + 47 km 201 m + 665 m= km

3 Solve.

a What is the total length, in cm and mm, when 125mm

is added to 40 cm 8 mm? P 7 200 R
b The distance from Qto Ris 642 m
m 173

more than the distance from Pto Q.

What is the distance, in km and m, from Pto R? Q

TEACHER’S Drill conversion of units using flash cards.
NOTES
12.3 (i)
b

Subtraction of length

1 What is the difference of length between the two keys shown in the
pictures below?

5 cm 6 mm – 3 cm 2 mm = cm mm

cm mm 5 cm 6 mm 3 cm 2 mm

56
–3 2

24

5 cm 6 mm – 3 cm 2 mm = 2 cm 4 mm
The difference of length between the two keys is 2 cm 4 mm.

2 28 cm 6 mm – 8 mm – 13 cm 5 mm = mm

Method 1 Method 2

cm mm cm mm 7 16 2 7 8 mm
– 13 5 mm
27 16 27 8 2 8 6 mm
– 13 5 – 8 mm 14 3 mm
28 6
14 3 2 7 8 mm
– 8

27 8

14cm 3 mm = 140 mm + 3 mm
= 143 mm

28 cm 6 mm – 8 mm – 13 cm 5 mm = 143 mm

Which method would you choose? Why?

3 78 km 607 m – 23 km 179 m = km m

km m

78 9
– 23 5 1017

6 07

179

55 428

78 km 607 m – 23 km 179 m = 55 km 428 m

TEACHER’S Encourage pupils to check the answers using addition.
NOTES
12.4 (i)
174 a, b

4 12 km 742 m – 145 m – 3 km 415 m = m

km m km m

12 13 12 5 9 7 9 km 182 m = 9 000 m + 182m
– 6 3 12
– 3 4 15 = 9 182 m
742

14 5

12 5 9 7 9 18 2

12 km 742 m – 145 m – 3 km 415 m = 9 182 m

5 32 km 720 m

8 km 950 m 15km 785 m

AB C D

What is the distance from Cto Dbased on the diagramabove?

32 km 720 m – 8 km 950 m – 15 km 785 m = km m

km m km m Convert 1km to 1000 m.

2 11 1612 161610
3 1 17 2 0 2 2 177 0

32 720 23 770

– 8 9 50 – 15 7 8 5

23 770 7 9 85

32 km 720 m – 8 km 950 m – 15 km 785 m = 7 km 985 m
The distance from Cto Dis 7 km 985 m.

First, add 8 km 950 m and 15km 785 m. Then, subtract the
answer from 32 km 720 m. Is the answer thesame?

Calculate.

a 94 cm 9 mm – 2 mm = cm mm

b 90 km 898 m – 47 km 288 m = km m

c 1071km – 67 km – 192 km = d km

e 76 cm 3 mm – 33 cm 5 mm – 7 mm = mm

77 km 28 m – 9 km 35 m – 11km 943 m = m

TEACHER’S http://www.bbc. uk/bitesize/ks2/maths/shape_space/measures/read/2/
NOTES
12.4 (i) 175
b

Multiplication of length

1 Ribbon Length

Pink 32 cm 2 mm

White 61cm 5 mm

The table above shows the lengths of ribbons for two types
of bows.

a What is the length of ribbon needed to make 3 pink bows?

3 × 32 cm 2 mm = cm mm

cm mm
32 2
×3

96 6

3 × 32 cm 2 mm = 96 cm 6 mm
The length of ribbon needed for 3 pink bows is 96 cm 6 mm.

b Calculate the total length of ribbon, in cm, for 8 white bows.

8 × 61 cm 5 mm = cm

Method 1 Method 2

cm mm cm mm
61 5 61 5

×8 ×8

488 40 488 40
+ 4 – 4 0 4 × 10mm
488 cm 40 mm = 488 cm + 4 cm
= 492 cm 492 0

8 × 61 cm 5 mm = 492 cm

The total length of ribbon, in cm, for 8 white bows is 492 cm.

12.5 (i) TEACHER’S Drill multiplication of length, with or without conversion of units.
a NOTES Carry out activities like quiz and cross number puzzle to reinforce pupils’
understanding.
176

2 The distance of 1round of go-kart circuit is 5 km 602 m. Calculate
the distance covered in 4 rounds.

4 × 5 km 602 m = km m

km m km m

5 602 2
×4
5 602
2408 ×4

22 408

4 × 5 km 602 m = 22 km 408 m
The total distance covered in 4 rounds is 22 km 408 m.

3 6 × 8 km 278 m = m

8 km 278 m = 8 000 m + 278 m 1 44
= 8 278 m
8 278m
×6

49 668m

6 × 8 km 278 m = 49 668 m

Multiply first. Then, convert km to m.
Is this method easier?

Solve.

a 2 × 9 cm 3 mm = cm mm b 6 × 36 cm 4mm = mm
km m
c 5 × 18cm 2 mm = cm mm d 8 × 61km 24 m =
km m
e 3 × 4 km 118m = m f 7 × 35 km 302 m =

g Multiply 8 by 2 108 m. Give answer in km and m.

TEACHER’S Drill multiplication using flash cards and check the answers using calculator.
NOTES
12.5 (i) 177
b

Division of length

1 What is the length of one part of the wood?

72 cm 9 mm ÷ 3 = cm mm

2 4 cm 3 mm A wood which is 72 cm 9mm
long is cut into 3 equal parts.
3 )72 cm 9 mm

–6 –9
12 0

– 12
0

72 cm 9 mm ÷ 3 = 24 cm 3 mm

The length of one part of the wood is 24 cm 3 mm.

2 59 cm 4 mm ÷ 9 = mm

6 cm 6 mm
9 )5 9 cm 4 mm
6 cm 6 mm = 60 mm + 6 mm

– 5 4 + 50 = 66 mm

5 54

– 54 First, convert 59 cm 4 mm

0 to mm. Then, divide by 9.
Is this method easier?
59 cm 4 mm ÷ 9 = 66 mm

3 The total distance taken by Jane to music class for 7 days
is 49 km 721m. Calculate the distance taken by Jane in a day.

49 km 721 m ÷ 7 = km m

7 km 1 0 3 m

7 )4 9 km 7 2 1 m

– 49 –7
0 02
–0
21
– 21
0 49 km 721 m ÷ 7 = 7 km 103 m

The distance taken by Jane in a day is 7 km 103 m.

TEACHER’S Remind pupils to give answers in the required units.
NOTES
12.6 (i)
178 a, b

4 SEJAHTERA SUPERMARKET MURNI

PETROL STATION

MeGA SUPERMRKET

79 km 464 m

Murni Petrol Station is located 79 km 464 m ÷ 2 = km m

between SejahteraSupermarket 3 9 km 73 2 m
and Mega Supermarket. 464m
What is the distance from Murni 2 )7 9 km + 10 00
PetrolStationto MegaSupermarket?
–6 14 6 4
19

– 18 – 14

79 km 464 m ÷ 2 1 06

= km m –6

04

How do you solve this problem –4
to give the answer in m? 0

79 km 464 m ÷ 2 = 39 km 732 m

The distance from Murni Petrol Station to Mega Supermarket is
39 km 732 m.

60 km 600 m

The distance from Pto Ris 60 km 600 m.The P Q R

distance from Qto Ris 3 times thedistance

from Pto Q. What is the distance, in m, from Pto Q?

Solve. cm mm b 9 cm 2 mm ÷ 4 = cm mm
a 16cm 8 mm ÷ 2 = mm d 21km 819m ÷ 7 = km m
c 62 cm 5 mm ÷ 5 = km m f 5 km 715m ÷ 3 = m
e 79 km 200 m ÷ 6 =

12.6 (i) TEACHER’S Prepare question cards for division and carry out a quiz activity in groups. 179
b NOTES

Solve the problems

1 Zarul built 3 aeroplane models for Creativity
Club. For models A, Band C, Zarul used
cardboards measuring 15 cm 2 mm,
23 cm 5 mm and 13 cm 8 mm. Calculate
the total length, in mm, the cardboards used.

Given Cardboard A 15cm 2 mm, Cardboard B23 cm 5 mm,
Cardboard C13cm 8mm.

Find Total length of cardboards in mm.
Operation
Draw a diagram.

Addition

15cm 2 mm 23 cm 5 mm 13cm 8mm

Solve Total length mm

15cm 2 mm + 23 cm 5 mm + 13cm 8 mm =

cm mm 52 cm 5 mm = 520 mm + 5 mm
= 525 mm
11 2
5
15 8
23
+ 13

52 5

Check cm mm cm mm

5 1 15 38 7
–23 5
52 5
– 13 8 15 2

38 7

15cm 2 mm + 23 cm 5 mm + 13cm 8 mm = 525 mm

The total length of cardboards used is 525 mm.

TEACHER’S Guide pupils to solve problems using tables.
NOTES
180 12.7(i)

2 The distance from Mr Jagdish’s house to the meeting venue is 47
km 850 m. After driving for 998 m, he stops to fill petrol. He
continues his journey for another 35 km 810 m and stopsagain
at a rest area. What is the remaining of his journey, in km and m?

Given Distance from Mr Jagdish’s house to the meeting venue is
Find 47 km 850 m. Driving a distance of 998 m and stops
to fill petrol. Driving 35km 810 m and stops at rest area.

The remaining journey in km and m.

Operation Subtraction Total distance : 47 km 850 m

998 m 35 km 810m Remaining
distance

Meeting venue

Solve 47 km 850 m – 998 m – 35 km 810 m = km m

km m km m

1714 10 46 852
4 6 185 0 – 3 5 8 10

47 850 11 4 2
– 998

46 852

Check 47 km 850 m 48 km Estimate the
answer to the
998 m 1 km nearest km.

35 km 810m 36 km

48 km – 1km – 36 km = 11km

11km 42 m is close to 11km. The answer is
reasonable.

47 km 850 m – 998 m – 35 km 810 m = 11 km 42 m

The remaining distance of Mr Jagdish’s journey is 11 km 42 m.

12.7 (i) TEACHER’S Guide pupils to underline information or keywords based on the given problem and
NOTES solve it with various strategies.

181

3 Encik Ismail needs strings to tie 6 similar parcels of the same size.
Each parcel needs 60 cm 3 mm. What is the length of string, in
cm and mm, needed to tie all the parcels?

Given There are 6 parcels.
60 cm 3 mm of string for 1parcel.

Find Length of string needed for 6 parcels.

Operation Multiplication

60 cm 3 mm 60 cm 3 mm 60 cm 3 mm 60 cm 3 mm 60 cm 3 mm 60 cm 3 mm

Solve 6 × 60 cm 3 mm = cm mm

cm mm 360 cm 18mm = 360 cm + 10mm + 8 mm
60 3 = 360 cm + 1cm + 8 mm
× 6 = 361 cm 8 mm

360 18

Check

6 0 cm 3 mm Check your answer
8 mm by dividing it.
6 )3 6 1cm
+ 10
–3 6 18
01
– 18
–0 0
1

6 × 60 cm 3 mm = 361 cm 8 mm

The length of string needed to tie all the parcels is 361 cm 8 mm.

TEACHER’S Guide pupils to solve problems by simulation using real objects.
NOTES
182 12.7(i)

4 The Jalur Gemilang Run of 10 km 500 m will
be held in conjuction with Hari Kemerdekaan.
4 runners run in a relay, carrying the Jalur
Gemilang. What is the distance, in m,
of each runner?

Given The distance is 10km 500 m.
There are 4 runners.

Find The distance, in m, by each runner.

Operation Division Runner 1 Runner 2 Runner 3 Runner 4
10 km 500 m

Solve 10 km 500 m ÷ 4 = m

2 km 625m
5 0 0m
4 )10 km

– 8 + 2 0 00

2 2500 2 km 625 m = 2 000 m + 625 m
= 2 625 m
–24
Check by multiplying
10 2 km 625 m by 4.

–8

20

– 20

0

Check km m

2 12

2 625
× 4

10 5 0 0

10km 500 m ÷ 4 = 2 625 m

The distance of each runner is 2 625 m.

12.7 (i) TEACHER’S Ensure that pupils check the answers and explain the importance of checking them.
NOTES 183

Solve.

a Tarmizi draws three straight lines with the lengths of 12cm 4 mm,
8 cm 6 mm and 15cm 9 mm respectively. What is the total length of
the three straight lines?

b Mei Chu recorded the measurements of leaves that she brought for
Science experiment as shown in the picture.
Calculate the total length of the leaves.

c
7 cm 7mm
30mm
41 mm

12km 18 m Mr Singam’s
House
Office Music Class

The diagram shows the distance between the office and the music
class. The distance from Mr Singam’s house to the music class is
3 km 120 m less than the distance from music class to the office.
What is the distance from his house to the music class?

d. Rizal’s pencil is 12cm long. Lily’s pencil is 3 cm 4 mm longer than
Rizal’s pencil. What is the total length, in mm, of their pencils?

e. The table shows the distance to Taman Setia and Taman Anggerik
from Taman Kenanga.

Place Distance from Taman Kenanga

Taman Setia 10km 217m

Taman Anggerik ?

The distance from Taman Kenanga to Taman Anggerik is 3 times the
distance from Taman Kenanga to Taman Setia. What is the distance,
in m, from Taman Kenanga to TamanAnggerik?

f The width of a book is 3 times Dahlia’s hand span. The width of the book
is 36 cm 3 mm. What is the length of Dahlia’s hand span?

TEACHER’S
NOTES

18844

Materials Ruler, pencil, pen and Players 5 pupils in a group.
location map.

Kesuma Jaya Town is a new town. Suggest the locations for a recreational
park, a school and a mini library based on the estimated distance of 1km
in the plan and the rules given.

Rules

a. The distance of the recreational park is 1km less than the lake so that
citizens can go fishing and cycling around the lake.

b. The distance of the mini library is between 1km to 2 km from the
community hall.

c. The school is located between the recreational park and the mini
library with an estimated distance of 3 km.

K E S U M A JAYA TOWN PLAN

Multipurpose Shop

X

1km

X X

Community Hall Police Station

Lake X

Steps

1 Mark X at the suggested location. Draw the distance and label the
name of the location.

2 Add other necessary facilities. State why do you need the facilities.

3 Discuss the outcomes of your group work.

4 Display it at the Mathematics corner.

TEACHER’S Make enough copies of the location map for each group.
NOTES
7.6 (i) 185

1 Measure the length of each object. Write the measurement.
ab
mm cm mm

2 Fill in the blanks. b 2 576 m = km m
a 62 mm = cm mm d km 212m = 16212m
c cm 5 mm = 85 mm

3 The distance of X and Yis given. Estimate the distance from Yto Z.

a 1km b 4 km
XY ZX
Y Z

4 Complete the following.

a. 26 cm 8 mm – 8 cm 8 mm = cm

b.18cm 9 mm ÷ 9 = cm c mm

d e14fcm 7 mm + 6 mm + 5 cm 5 mm = mm

3 × 12cm 8 mm = cm mm

7 × 6 km 404 m = m

53 km 124 m ÷ 4 = km m

5 Solve.

a. The distance from Azrul’s house to school is 3 km 742 m.
Calculate the total distance, in km and m, travelled by Azrul for
3 days, back and forth toschool.

b. A length of wire measuring 74 cm 5 mm, need to be cut into

5 equal parts. What is the length of one part of the wire inmm?

cP 25 cm QThelengths of the lines Xand Yare
X less than the line PQas
Y
80 mm shown in the diagram. Calculate

120 mm the difference in length, in mm,
the lines X and Y.

TEACHER’S
NOTES

18866

13 School
MASS

Addition and subtraction of mass

1 Oh, uncle you have over weighed the
beans! Can you make it 150 g lesser?
Azim, how many grams
do you want to buy?

10kg

1kg 900 g 0
500
400 gram 100

300 200

Crackers
2 kg

What is the total mass of the items bought?
2 kg + 400 g – 150 g = kg g

kg g kg g

2 000 2 3 10
+ 400 –
40 0 400
2 2 150
2 50

2 kg + 400 g – 150 g = 2 kg 250 g

The total mass of the items bought is 2 kg 250 g.

Add the two masses of dodol. What is the 1kg 900 g
difference in mass between the dodol and the
crackers bought?

13.1(i) TEACHER’S Add and subtract masses based on situations and simulation activities. 187
NOTES Explain that adding and subtracting units of masses is the same as adding
and subtracting whole numbers.

2 10 kg 80 g – 3 kg 450 g + 2 kg 370 g = kg

kg g 450 g connot be subtracted from 80 g.

9 1080 10 kg 80 g = 9 kg + 1000 g + 80 g
= 9 kg 1080 g
10 8 0
kg g
– 3 450
6 63 0 1 1

6 630 630 g + 370 g = 1000g
+2 = 1kg
370
9
00 0

10 kg 80 g – 3 kg 450 g + 2 kg 370 g = 9 kg

3 26 kg + 8 760 g – kg g = 4 815 g

Convert 26 kg 1 13 175 10 × 1000
to 26 000 g. 23 kg g
26 000 g 760 g
34 8 15 g ÷ 1000
+ 8 760 g –4 9 45 g
INFORMATION
34 760 g 29

29 945 g = 29 kg 945 g

26 kg + 8 760 g – 29 kg 945 g = 4 815 g

1kg 500 g 1kg 50 g 1kg 550 g

PQ R

Determine the 2 packets of biscuits that should be mixed first.

Then, reduce 100 g so that the mass becomes 2 500 g.

188 13.1(i) TEACHER’S Pay attention on regrouping from g to kg.
NOTES Emphasise on conversion for values more than 1000 g.

Materials Weighing scale, pebbles, exercise book.

Players 4 pupils in each group.

Steps

1 The first pupil weighs a few pebbles and record its
mass.

2 The second pupil adds more pebbles and
record its mass. For example, add 600 g of pebbles.

3 The third pupil takes out some pebbles and record
the mass of pebbles left.

4 The fourth pupil writes the complete number
sentence involving addition and subtraction.

5 Discuss and solve the number sentence in groups.

1 Calculate.

a 4 kg 820 g + 5 kg 100 g – 1kg 694 g = kg g

b 9 kg – 3 016 g + 1kg 110g = kg g

c d30ekgf 60 g – 22 kg 445 g + 1kg 32 g = g

27 kg 510 g + 7 kg 390 g – 18kg 900 g = kg

16kg 450 g – 9 480 g + 4 kg 30 g = kg

10 kg + 6 kg 5 g – 2 080 g = g

2 Subtract 3 510 g from the sum of 7 kg 30 g and 4 kg.

3 12 kg 9 kg 78 g 9 kg 200 g

Based on the cards above add the heaviest mass to the second
heavy mass. From the answer, subtract the lightest mass.

13.1(i) TEACHER’S Diversify activities such as cross number puzzles, simulations and games to
NOTES reinforce the concept of mixed operations.

189

Multiplication and division of mass

1 Hadi, please repack these

3 packs of crisps into 8
smaller packs.

Based on the picture, g crisps
what is the mass of
crisps in 1small pack? 50
kilogram 1
3 × 1 200 g ÷ 8 = 4
32

1 200g 450 g
×3 8 3 600 g
–3 2
3 600g
40
– 40

00
–0

0

3 × 1 200 g ÷ 8 = 450 g
The mass of crisps in 1small pack is 450 g.

2 8 x 2 kg 500 g ÷ 4 = kg

2 kg g Why subtract 1000 g
2 500 and add 1kg? Explain.
8 × 2 kg 500 g ×2
4 10 0 0
4 + 1 – 10 0 0

1 50

8 × 2 kg 500 g ÷ 4 = 5 kg

190 13.1(ii) TEACHER’S Guide pupils to multiply and divide units of mass through simulation or based on
NOTES given situation.

3 18 kg 945 g ÷ 9 × 2 = g

2 kg 105 g kg g
9 18 kg 9 45 g
–18 – 9 1

0 04 2 105
–0 ×2

4 210
45
– 4 5 4 kg 210 g = 4 000 g + 210g

0 = 4 210 g

18 kg 945 g ÷ 9 × 2 = 4 210 g

First, multiply 9 by 2. Then, divide
18kg 945 g by the product. Is the
answer the same?

4 31 kg ÷ 5 × 10 = kg

Method 1 6 kg 2 0 0 g kg g
6 200
5 3 1kg 0g × 10
6 0 2000
–30 + 100 0
60 kg 2 000 g = 60 kg + 2 kg
1 10 0 0 = 62 kg

– 10 Which method do you
choose? Why?
00

–0

00

–0

0

Method 2 2

31kg × 10
= 31kg × 2

5
1 = 62 kg

31 kg ÷ 5 × 10 = 62 kg

13.1(ii) TEACHER’S Expose various strategies involving multiplication and division to enhance
NOTES pupils’ understanding.

191

200 g
4 kg

Each has the same mass. What is the mass of , in g?

Players 4 to 6 pupils. Materials Mass cards, symbol cards,
Steps number cards, envelopes.

1 Teacher prepares a few number cards, mass cards and symbol cards.
Examples: 2 770 g – = 6 kg 550 g 10 kg 480 g + 6 kg 700 g (set 1)

8 350 g = 10 kg 20 g 6 ÷ × 5 (set2)

2 Keep 1set of cards in an envelope.
3 Teacher gives an envelope filled with the same set of cards to each

group.
4 Pupilsarrange the cards to form a complete and correct number sentence.
5 Thefastest group with the correct number sentence is given 5 marks. Other

groups are given 3 marks each.
6 Repeat steps 2 to 5 for different sets of cards.
7 The group that scores the highest mark is the winner.

Calculate.

a 5 × 8 kg 60 g ÷ 10= kg g b 4 × 6 kg 300 g ÷ 6 = g
kg
c 10× 9 kg ÷ 12 = kg g d 40 kg 500 g ÷ 9 × 10 = g

e 21kg ÷ 5 × 3 = kg g f 19 kg 110 g ÷ 7 × 8 =

192 13.1(ii) TEACHER’S Diversify activities involving mass for mixed operations in co-curriculum such as
NOTES cooking competition.