Page 58 - Start Up Mathematics_7

(b) 19.1484 ÷ 3.24
Alternative method:
Converting divisor to a 19.1484 ÷ 3.24 = 1,91,484 ÷ 324
whole number, we get 10,000 100

19.1484 = 19.1484 × 100 = 1,91,484 × 100
3.24 3.24 × 100 10,000 324
1,914.84 1,91,484 1 594
= = × = = 5.91
3.24 324 100 100
= 5.91

Example 22: Find: (a) 3.25 ÷ 0.5 (b) 30.94 ÷ 0.7
Solution: (a) 3.25 ÷ 0.5 Alternative method:
325 5
3.25 = 3.25 × 10 = 32.5 3.25 ÷ 0.5 = 100 ÷ 10
0.5 0.5 × 10 5 325 10
5 32.5 6.5 = 100 × 5
–30 325 1
25 = 5 × 10
–25 65
0 = 10 = 6.5

Proceeding as above, we get
(b) 30.94 ÷ 0.7 = 44.2

Example 23: A truck covers a distance of 43.2 km in 2.4 hours. How much distance will it cover
in 1 hour?
Solution: Distance covered in 2.4 hours = 43.2 km

∴ Distance covered in 1 hour = 43.2 ÷ 2.4
432 24 432 10
= ÷ = × = 18 km
10 10 10 24
EXERCISE 3.3

1. Find:
(a) 234.56 ÷ 10 (b) 34.78 ÷ 10 (c) 0.0056 ÷ 10 (d) 0.0236 ÷ 10

2. Divide the following:
(a) 534.057 ÷ 100 (b) 134.078 ÷ 100 (c) 1.0356 ÷ 100 (d) 0.0059 ÷ 100

3. Evaluate the following:
(a) 1,234.56 ÷ 1,000 (b) 384.734 ÷ 1,000 (c) 2.0056 ÷ 1,000 (d) 23,598 ÷ 1,000

4. Calculate:
(a) 547.56 ÷ 12 (b) 30.51 ÷ 15 (c) 14.0784 ÷ 14 (d) 8.65755 ÷ 2.7
5. Divide the following decimal numbers:

(a) 4.56 ÷ 0.0456 (b) 134.78 ÷ 0.4 (c) 0.0056 ÷ 0.07 (d) 0.0232 ÷ 0.8

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