Chapter 9

Length
 

Page 167

Practice 1 Measuring in Metres

(1)
Look at the pictures.
Fill in the blanks with more or less.
(a)
The length of the rope is less than 1 m

(b)
The length of the bicycle is more then 1 m

(c)
The height of the calendar is less than 1 m.

(2)
Look at the table below.
Tick (v) the columns that are true.
You will need a metre stick or a 1-metre string to measure
some items.

Page 169

Practice 2 Using Metres to Compare and Order Lengths

Fill in the blanks.
(1) Look at the ropes.
Their lengths are given.
Rope B 3m
Rope A 11 m
(a) Which rope is longer? Rope A
(b) How much longer is it? 8 m

(2) Look at the sides of the rectangle.
Side A 19m
Side B 12m
Which is shorter, Side A or Side B?
Side B

(3) Look at the giraffes.
Their heights are given.
Giraffe A 8m

Giraffe B 3m

Giraffe C 5 m

(a) Which giraffe is the tallest? Giraffe A
(b) Which giraffe is the shortest? Giraffe B
(c) Arrange the giraffes from tallest to shortest.
A             C             B
tallest

(4) Look at the buildings.
Their heights are given.

Building A 32 m

Building B 20m

Building C 75m

(a) Which building is the shortest? Building B
(b) Which building is the tallest? Building C
(c) Arrange the buildings from shortest to tallest.
B             A             C
shortest

Page 171

Practice 3 Measuring in Centimetres

(1) Fill in the blanks.

(a) The pencil is 8 cm long.
(b) The eraser is 3 cm long.

(2) Fill in the blanks.

(a) The length of the comb is  5 cm
(b) The length of the ribbon is 7 cm.
(c) The length of the eraser is 2 cm.

(3) Tick (•) the correct way to measure the length of the pencil.
Tick 8 cm

(4) Use your centimetre ruler to measure the length of each line,
(a)
The line is 5 cm long.

(b)
The line is 12 cm long.

(c)
The line is 9 cm long.

(5) Use your centimetre ruler to draw,
(a) Draw a line 6 cm long.

(b) Draw a line 2 cm shorter than the line in (a).

(6)
Use your centimetre ruler to draw.
(a) Draw a line 5 cm long. Name it Line X.

Draw a line 6 cm longer than Line X. (11 cm)

(b) Draw a line 10 cm long.

(7)
Use a piece of string and a centimetre ruler to find the length
of each line.
(a)
5 cm
(b)
4 cm

(c) With the same piece of string used in (a), form another line.
Paste the string here.
Answers vary.

Does it have the same length as the line in (a)? Yes

(8)
Cut a piece of string of the same length as the drawing below.
Then, place the string on a centimetre ruler to find its length.
string
(a) How long is the string? 9 cm
(b) The same piece of string is used to form the following lines.

Do they all have the same length? Yes

Page 175

Practice 4 Using Centimetres to Compare and Order Lengths

(1) Fill in the blanks.

(a) The wallet is 13 cm long.
(b) The key is 6 cm |ong
(c) The pencil is 12 cm long.
Fill in the blanks with longer or shorter.
(d) The wallet is longer than the pencil.
(e) The key is shorter than the pencil.
(f) Arrange the objects from longest to shortest.
wallet             pencil             key
longest

(2) Use your answers in (1).
Fill in the blanks.
(a) The wallet is 7 cm longer than the key.

(b) The key is 6 cm shorter than the pencil.
(c) The pencil is 1 cm shorter than the wallet.

(3) Fill in the blanks.

(a) Ribbon A is 8 cm long.
(b) Ribbon B is 7 cm long.
(c) Ribbon C is 10 cm long.
(d) Ribbon C is the longest.
(e) Ribbon B is the shortest.
(f) Arrange the ribbons from shortest to longest.
B            A             C 
shortest        

(4) Fill in the blanks.

(a) The paper clip is 3 cm long.
(b) The pencil is 14 cm long.
(c) The stapler is  9 cm long.
(d) The paper clip is 6 cm shorter than the stapler.
(e) The pencil is 5 cm longer than the stapler.
(f) The paper clip is 11 cm shorter than the pencil.
(g) Arrange the objects from longest to shortest.
pencil             stapler             paperclip
longest

(5) Fill in the blanks.

(a) Hafiz's pencil is 10 cm long.
(b) Joan's pencil is 13 cm long.
(c) Binghui's pencil is 8 cm long.
(d) Hafiz's pencil is 3 cm shorter than Joan's pencil.
(e) Joan's pencil is 5 cm longer than Binghui's pencil.
(f) Hafiz's pencil is 2 cm longer than Binghui's pencil.
(g) Arrange the pencils from longest to shortest.
Joan's pencil             Hafiz's pencil             Binghui's pencil
longest

Page 179

Practice 5 Addition and Subtraction of Length

We are happy that pupils of all races live happily together.
We celebrate this on 21 July every year.
What day is this? Match the letters to the numbers to find out.

(1) Add.

|2| Subtract.

Now, match the letters to the numbers to find out.

(3) A can of beans is 14 cm tall.
A can of sardines is 6 cm shorter than the can of beans.
How tall is the can of sardines?

14 - 6 = 8
The can of sardines is 8 cm tall.

(4) There are two pictures.
One of them is 35 cm long.
The other is 86 cm long.
They are placed side by side.
What is the total length of the two pictures?

35 + 86 = 121
The total length of the two pictures is 121 cm.

(5)
A piece of cloth is cut into three pieces.
They are 4 m, 6 m and 2 m long.
How long was the piece of cloth before it was cut?

4+6+2=12
The piece of cloth was 12 m long.

(6)
A piece of wood is 500 cm long.
Mr Sylvia cuts it into two pieces.
The first piece is 135 cm long.
How long is the second piece?

500-135 = 365
The second piece is 365 cm long.

(7)
Nurul has a strip of paper 20 cm long.
Her strip of paper is 48 cm shorter than Lenny's.
How long is Lenny's strip of paper?

20 + 48 = 68
Lenny's strip of paper is 68 cm long.

(8) Jinghui walked 200 m.
He walked 63 m further than Peiwen.
How far did Peiwen walk?

200-63=137
Peiwen walked 137 m.

(9) Mrs Chu has 2 sticks.
The red stick is 19 cm long.
The yellow stick is 22 cm long.
How much longer is the yellow stick than the red stick?

22-19=3
The yellow stick is 3 cm longer than the red stick.

(10) A flag pole is 450 cm tall.
The top of the flag is 345 cm from the ground.
How much farther must it be raised to reach the top?

450-345=105
The flag must be raised 105 cm farther to reach the top.

Page 185

Practice 6 Multiplication and Division of Length

Solve.
(1) Mrs Lim buys 8 poles.
Each pole is 3 m long.
What is the total length of the 8 poles?
8 x 3=24
The total length of the 8 poles is 24 m.

(2) Jasper had a piece of ribbon.
He cut it into 6 smaller pieces.
Each piece was 10 cm long.
How long was the piece of ribbon at first?
6x10=60
The piece of ribbon was 60 cm long at first.

(3) Alice's rope is 45 cm long.
She cuts it equally into 5 pieces.
How long is each piece of rope?
 45 ÷ 5 = 9
Each piece of rope \s 9 cm long.

(4) Mr Yap had a piece of wood that is 30 cm long.
He cut it equally into pieces.
Each piece was 5 cm long.
How many pieces did he cut the wood into?
30 ÷ 5 = 6
He cut the wood into 6 pieces.

(5) A rope, 40 cm long, is cut equally into 4 pieces.
How long is each piece?
40 ÷ 4 = 10
Each piece is 10 cm long.

(6) Mdm Sharifah used 28 m of cloth to make some curtains.
She used 4 m of cloth for each curtain.
How many curtains did she make?
28 ÷ 4 = 7
She made 7 curtains.

Page 188

Maths Journal

What unit of length (m or cm) will you choose to measure the objects?
Explain your choice.

Page 189

Performance Task

On the table, you have a centimetre ruler, a string and a measuring tape.
Your teacher has the metre rule.
Approach your teacher when you need it.
Use the correct measuring item to answer the following questions.
Remember to write the units next to your answer.
(1) Your teacher gives out four strips of paper labeled A, B, C and D.
Find the length of each strip of paper. Answers vary.
(a) The length of Strip A is __
(b) The length of Strip B is __
(c) The length of Strip C is __
(d) The length of Strip D is __
(e) Which is the longest strip? Strip _
(f) Which is the shortest strip? Strip _
(g) Arrange the strips from longest to shortest.

__________________    __________________    ______________________
longest
(2) Measure the length of the line below.
8 cm

Page 190

Challenging Practice

(1) There are two lines — A and B.
Line A is shown below.
Line A

Line B is 2 cm longer than Line A.
How long is Line B?
Draw Line B.
Line B

(2) Sara bought three pieces of ribbon.
She bought 90 cm of ribbon altogether.
Tick (•) to show which three pieces of ribbon she bought.

Page 192

Problem Solving

Mr Lin hangs lanterns along the school's corridor for Chinese New Year.
He places the lanterns 1 m apart from each other, beginning at one end
of the corridor.
The corridor is only long enough to place 6 lanterns.
What is the length of the corridor?
Draw a diagram to help you.

1m 1m 1m 1m 1m

The corridor is 5 m long.
 

Page 193

Revision 1

(1) What is the number shown in the place value chart?

Hundreds	Tens	Ones

The number shown is 450

(2) How many flowers are there?

7 x 5 = 35

There are 35 flowers.

(3) Write 619 in words.
six hundred and nineteen

(4) Fill in the blanks.
110 ., 114,118,122,126, 130, 134, 138

(5) Arrange the numbers from greatest to smallest.
Use the place-value chart to help you.

333, 133, 331, 313

333         331         313         133
greatest

(6) Fill in the blanks.
21,18,15,12, 9, 6
(7) Circle the odd numbers.
Cross out the even numbers.
 

(8) Add.

(9) Subtract.

(10) Add 46 and 63.
    4 6
+  6 5
   109

(11) Subtract 17 from 831.
   2 11
8 3  1
-  1  7
 8 1  4

(12) Write a multiplication equation and a related division equation.

(a) 3 x 6 =18 or 6 x 3=18

(b) 18 ÷ 3 = 6 or 18 ÷ 6 = 3

(13) Fill in the blanks.
(a) Skip count by 2s.

4    6    8    10    12    14    16    18    20

(b) Skip count by 3s.

3    6    9    12    15    18    21    24    27    30

(c) Skip count by 5s.

5    10    15    20    25    30        35    40    45    50

(14) Multiply,

(a) 2 x 4 = 8
(b) 4 x 5 = 20
(c) 7x3 = 21
(d) 8 x 10 = 80
(e) 5 x 5 = 25
(f) 5x7 = 35.
(g) 9x4 = 36
(h) 10x10= 100
(i) 5x7 = 35
(j) 9 x 5 = 45

(15)

(a) What is the length of this line?
The length of this line is 9 cm.

(b) Use a string and a centimetre ruler to measure
the length of this line.
The length of this line is 7 cm

(16) Fill in the blanks.

(a) The key is  4 cm |ong.
(b) The pencil is 7 cm long.
(c) The comb is 15 cm long.
(d) The brush is 11 cm longer than the key.
(e) The bookmark is 7 cm shorter than the comb.
(f) The comb /brush has the same length as the brush /comb
(g) The pencil is 3 cm longer than the key
(h) The total length of the brush, the pencil and the bookmark
is 30 cm.

Solve.
(17) Grace and Gabriel have 185 gift boxes altogether.
Grace has 137 gift boxes.
How many gift boxes does Gabriel have?

185  - 137 = 48

Gabriel has 48 gift boxes.

(18) There were some birds on a rooftop.
25 of them flew away.
There were 29 birds left on the rooftop.
How many birds were there on the rooftop at first?

25+29=54
There were 54 birds on the rooftop at first.

(19)
Jessie makes 116 paper cranes.
Jamie makes 131 more paper cranes than Jessie
How many paper cranes does Jamie make?

116+131= 247
Jamie makes 247 paper cranes.

(20)
Julia makes 120 pineapple tarts.
She makes 93 fewer pineapple tarts than Leila.
How many pineapple tarts does Leila make?

120 + 93 = 213
Leila makes 213 pineapple tarts.

(21) Maimun ran 352 m.
He ran 168 m further than Sufen.
How far did Sufen run?

352-168 = 184
Sufen ran 184 m.

(22) Justin spotted 8 nests.
There were 4 eggs in each nest.
How many eggs were there altogether?

8x4=32
There were 32 eggs altogether.

(23) Dylan invited 10 classmates to his birthday party.
He baked 70 cookies for them.
How many cookies would each classmate get?

70 ÷ 10=7
Each classmate would get 7 cookies.

(24) Liling bakes 50 gingerbread men.
She packs the gingerbread men into bags of 5.
How many bags does she need for all the gingerbread men?

50 ÷ 5=10
She needs 10 bags for all the gingerbread men.