Page 218 - SK Year 5 Mathematics DLP

SOLVE THE PROBLEMS

1 Cliff wants to form a right-angled triangle.
He uses three ropes and 12 cm 1 m
the measurements are as shown. 5

a Calculate the total length, in cm, of the
ropes.
0.16 m
b What is the difference, in m, between
the longest rope and the shortest rope?

1
Understand • The length of the ropes are 12 cm, 0.16 m, and m.
5
the problem • Calculate the total length of the ropes in cm.
• Find the difference between the longest rope and the
shortest rope in m.

Plan the strategy 1
12 cm m 0.16 m
5
total length
Solve

1 1
a 12 cm + m + 0.16 m = cm b m – 12 cm = m
5 5
1 = 20 cm – 12 cm
12 cm + m + 0.16 m
5 = 8 cm
1 20
= 12 cm + ( × 100) cm + (0.16 × 100) cm = (8 ÷ 100) m
5
1 = 0.08 m
= 12 cm + 20 cm + 16 cm

= 48 cm

Check b 0.08 m + 12 cm

a 4 8 cm 3 2 cm = 0.08 m + (12 ÷ 100) m
– 1 6 cm – 2 0 cm = 0.08 m + 0.12 m
3 2 cm 1 2 cm = 0.2 m

1 1
12 cm + m + 0.16 m = 48 cm m – 12 cm = 0.08 m
5 5
The total length of the ropes The difference between the longest

is 48 cm. rope and the shortest rope is 0.08 m.

210 • Guide pupils to find keywords in the questions and check
5.4.1
the answers using a calculator.