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MeASurIng LengTh

The base unit to measure length is the metre (m). It is also called the standard unit
of length.

Units of length larger than the metre Units of length smaller than the metre
are decametre (dam), hectometre (hm) are decimetre (dm), centimetre (cm)
and kilometre (km). and millimetre (mm).
1 dam = 10 m 1 m = 10 dm

1 hm = 100 m 1 dm = 10 cm
1 km = 1000 m 1 cm = 10 mm

Conversion of Bigger units of Length into Smaller units

If we want to convert a bigger unit into a smaller unit, we need to multiply the bigger
unit.
The following examples will help you understand the conversion of units of length.

example 1. Convert the following into centimetres.
a. 6 m b. 13 m 4 cm c. 3 m 50 cm
Solution. a. 6 m
We know that 1 m = 100 cm.
So, 6 m = 6 × 100 cm = 600 cm.
b. 13 m 4 cm = 13 m + 4 cm = (13 × 100) cm + 4 cm = 1300 cm + 4 cm = 1304 cm

c. 3 m 50 cm = 3 m + 50 cm = (3 × 100) cm + 50 cm

= 300 cm + 50 cm = 350 cm

example 2. Convert the following into metres.
a. 71 km b. 96 km 230 m
Solution. a. We know that 1 km = 1000 m.
So, 71 km = 71 × 1000 m = 71000 m.

b. 96 km 230 m = 96 km + 230 m = (96 × 1000) m + 230 m
= 96000 m + 230 m = 96230 m
example 3. Convert:
a. 6 m into dm b. 10 m into cm c. 8 cm into mm
Solution. a. 1 m = 10 dm
So, 6 m = (6 × 10) dm = 60 dm.

b. 1 m = 100 cm
So, 10 m = (10 × 100) cm = 1000 cm.
c. 1 cm = 10 mm
So, 8 cm = (8 × 10) mm = 80 mm.

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Measurement