Page 170 - Math Genius C4

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(c) We have 1 m = 10 dm
So, 7 m = (7 × 10) dm = 70 dm

7 m 9 dm = 70 dm + 9 dm = 79 dm
example 3: Convert 6 km 8 hm 5 dam 4 m into metres.

Solution: We know that

1 km = 1000 m, 1 hm = 100 m, 1 dam = 10 m

6 km 8 hm 5 dam 4 m = (6 × 1000) m + (8 × 100) m + (5 × 10) m + 4 m
= 6000 m + 800 m + 50 m + 4 m = 6854 m

conversion of Smaller units of Length into Bigger units

To convert a smaller unit into a bigger unit, we need to divide the smaller unit.

The following examples will help you understand the conversion of units of length.

example 4: Convert the following:

(a) 203 cm into m and cm (b) 3000 m into km
(c) 8250 m into km and m (d) 65 mm into cm and mm

(e) 5170 mm into m and mm

Solution: (a) We have 100 cm = 1 m

So, 203 cm = 200 cm + 3 cm = (200 ÷ 100) m + 3 cm

= 2 m 3 cm
(b) We have 1000 m = 1 km

So, 3000 m = (3000 ÷ 1000) km = 3 km

(c) We have 1000 m = 1 km
So, 8250 m = 8000 m + 250 m

= (8000 ÷ 1000) km + 250 m

= 8 km 250 m
(d) We have 10 mm = 1 cm

So, 65 mm = 60 mm + 5 mm

= (60 ÷ 10) cm + 5 mm
= 6 cm 5 mm

(e) We have 1000 mm = 1 m

So, 5170 mm = 5000 mm + 170 mm
= (5000 ÷ 1000) m + 170 mm

= 5 m 170 mm

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