Page 10 - Length

4.4 Writing lengths in different units

You already know the following:

• There are 10 millimetres in 1 centimetre.
• There are 100 centimetres in 1 metre.
• There are 1 000 metres in 1 kilometre.

1. (a) How many millimetres are there in 5 cm?
(b) How many centimetres are there in 20 mm?

(c) How many centimetres are there in 25 mm?

(d) What do you do to write a length which is given in
centimetres in millimetres?
(e) What do you do to write a length which is given in
millimetres in centimetres?

(f) Take a ruler and check your answers. Discuss this with a
classmate.

2. (a) How many metres are there in 6 km?
(b) How many kilometres are there in 3 000 m?

(c) How many kilometres are there in 7 500 m?

(d) What do you do to write a length which is given in
kilometres in metres?
(e) What do you do to write a length which is given in metres
in kilometres?

3. Write the following lengths in millimetres:
(a) 2 cm (b) 23 cm

(c) one half of a centimetre (d) one fifth of a metre

4. Write the following lengths in centimetres:
(a) 50 mm (b) 2 300 mm
(c) 7 m (d) 72 m

(e) 5 mm (f) 10 m

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