Page 120 - Start Up Mathematics_5

Look at the table given below. It shows how to change from bigger units to smaller units
and vice versa.

Multiply by 10 to go to a smaller unit

× 10 × 10 × 10 × 10 × 10 × 10
kilometre hectometre decametre METRE decimetre centimetre millimetre

(km) (hm) (dam) (m) (dm) (cm) (mm)
× 1 × 1 × 1 × 1 × 1 × 1
10 10 10 10 10 10

Divide by 10 to go to a bigger unit or multiply by 1
10

Remember
In metric system, the given prefixes have a fixed value:

• kilo – 1,000 • hecto – 100 • deca – 10
1 1 1
• deci – • centi – • milli –
10 100 1000

Example 1: Convert 1 hectometre to decimetre. × 10 × 10 × 10

Solution: 1 hm = 1 × 10 × 10 × 10 dm = 1,000 dm hm dam m dm
Example 2: Convert 3 millimetre to metre. m dm cm mm
1
1
1
Solution: 3 mm = 3 × 1 × 1 × 1 m × 10 × 10 × 10
10 10 10
= 3 × 1 m = 3 m
1000 1000 A Challenge!

Example 3: Convert 7 km 65 m to metres. Fill in the blanks.

Solution: 7 km 65 m = 7 km + 65 m (a) 4.25 km = ______ cm
7 km = 7 × 1,000 m = 7,000 m (b) 0.36 hm = ______ dm
(c) 9.8 dm = ______ dam
So, 7 km 65 m = 7,000 m + 65 m = 7,065 m.
(d) 726 mm = ______ dam
Weight

Just like length, weight also has a standard unit in metric system that is gram (g).
Let’s now learn to change units of weight from bigger to smaller units and vice versa.

× 10 × 10 × 10 × 10 × 10 × 10
kilogram hectogram decagram GRAM decigram centigram milligram
(kg) (hg) (dag) (g) (dg) (cg) (mg)
× 1 × 1 × 1 × 1 × 1 × 1
10 10 10 10 10 10

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