Page 144 - Cambridge+Checkpoint+Mathematics+Coursebook+9

15.1 Converting units of area and volume

) Exercise 15.1

1 Convert:
a 4 m to cm b 0.5 m to cm c 1.65 m to cm 2
2
2
2
2
2
d 8 cm to mm e 0.8 cm to mm f 12.4 cm to mm 2
2
2
2
2
2
g 50 000 cm to m h 42 000 cm to m i 8000 cm to m 2
2
2
2
2
2
j 900 mm to cm k 760 mm to cm l 20 mm to cm .
2
2
2
2
2
2
2 Convert:
a 7 m to cm b 0.75 m to cm c 1.2 m to cm 3
3
3
3
3
3
d 3 cm to mm e 0.4 cm to mm f 6.35 cm to mm 3
3
3
3
3
3
g 6 000 000 cm to m h 350 000 cm to m i 12 300 000 cm to m 3
3
3
3
3
3
3
3
3
3
j 4000 mm to cm k 540 mm to cm l 62 500 mm to cm .
3
3
3 Convert:
a 60 cm to ml b 125 cm to ml c 4700 cm to ml
3
3
3
d 8000 cm to litres e 2400 cm to litres f 850 cm to litres
3
3
3
3
3
3
g 3 litres to cm h 4.2 litres to cm i 0.75 litres to cm .
The shape of Tina’s kitchen is a rectangle 925 cm long by 485 cm wide.
4 The shape of Tina’s kitchen is a rectangle 925 cm long by 485 cm wide.
a Work out the area of Tina’s kitchen in square metres. Remember to use estimation
Show how to use estimation to check your answer. to check your answer; round
Flooring costs $56 per square metre. each number in the question
It is only sold in whole numbers of square metres. to one signifi cant fi gure.

b How much does Tina pay to buy flooring for her kitchen floor?

Show how to use inverse operations to check your answer.
5 Li is going to paint a door that measures 195 cm by 74 cm.
He is going to give it two layers of paint on each side.
One tin of paint covers 5 m .
2
How many tins of paint does Li need to buy?
Show how to check your answer.
35 cm
6 Chin-Mae has a fishtank that measures 75 cm by 45 cm by 35 cm.

He also has a jug that holds 1.75 litres. 45 cm
He uses the jug to fill the fishtank with water. 75 cm

How many full jugs of water does it take to fill the fishtank?
Show how to check your answer. Large jar
Small jar
7 Eloise makes 1.2 litres of salad dressing.
She stores the salad dressing in jars of two different sizes, as shown.
Each jar has a square base. 12 cm 16 cm

She fills the jars to the heights shown.
a Work out the volume of the large jar. 2.5 cm 3.5 cm

Eloise works out that she can fill at least 10 large jars with salad dressing.
b Without actually calculating the number of large jars

that Eloise can fill, explain whether you think
this is a reasonable answer or not.
Eloise wants to store the dressing in a mixture of large
and small jars.
c What is the best way for Eloise to do this?
15 Area, perimeter and volume 143