Page 109 - Start Up Mathematics_5

Example 13: Divide 9.25 by 2.

4 . 6 2 5
Solution:
2 9 . 2 5 0 Notice the added zero
– 8 ↓ Remember
1 2 If the remainder is not zero,
– 1 2 keep adding zeros to the
0 5 dividend and continue
– 4 dividing till you get the
1 0 remainder zero.
– 1 0
0

Division by 10, 100, 1,000, ...

To divide a decimal number by 10, 100, 1,000, etc. shift the decimal point to the left as many
places as the number of zeros in the divisor. For example,
• to divide by 10, move the decimal point one place to the left.
• to divide by 100, move the decimal point two places to the left.

• to divide by 1,000, move the decimal point three places to the left.

Example 14: Divide (a) 617.3 ÷ 10 (b) 12.756 ÷ 100 (c) 6.93 ÷ 1,000
Solution: (a) 617.3 ÷ 10 = 61.73 617 . 3 (b) 12.756 ÷ 100 = 0.12756 12 . 756

(c) 6.93 ÷ 1,000 = 0.00693 006 . 93
Quick Tip
A Challenge! To multiply, shift To divide, shift

the decimal point the decimal point
0.024 ÷ 100 = ? to the right. to the left.

. .

EXERCISE 7.4

1. Divide and verify your answer using the rule, Dividend = Divisor × Quotient + Remainder.

(a) 58.73 ÷ 7 (b) 139.36 ÷ 8 (c) 21.78 ÷ 3 (d) 0.7432 ÷ 12 (e) 406.39 ÷ 4
2. Divide till you get the remainder zero.

(a) 7.3 ÷ 8 (b) 85.08 ÷ 12 (c) 80.4 ÷ 5 (d) 426.75 ÷ 2 (e) 9.235 ÷ 4
3. Fill in the blanks.

(a) 90.62 ÷ 10 = ______ (b) 1.57 ÷ 100 = ______ (c) 417.81 ÷ 100 = ______
(d) 39.062 ÷ 10 = ______ (e) 246.75 ÷ 1,000 = ______ (f) 3.998 ÷ 1,000 = ______

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