Page 89 - ICSE Math 5

Exercise 6.3

1. Find the following products.
4 3 2 4 3 6 6
(a)  (b)  (c)  (d)  3
9 8 3 5 7 11 21
2. Find the following.

7 3 9 5
(a) of 108 (b) of 84 (c) of ` 39 (d) of 96 km
12 2 13 6
3. Multiply the following. Reduce to the lowest terms or a mixed fraction, if possible.
3 8 4 7 1
(a) × 49 (b) × (c) × 4
7 19 9 13 13
5 14 1 3 1 1
(d) 3 × 2 (e) 3 × 18 (f) 2 × 4 × 1
7 15 4 14 5 6
4. Fill in the blanks.
51 _____ 8 3 _____ 8
(a)  0 = (b)  = 
64 5 7 5
2 _____ 5 2 1 5 75 _____
(c)   =   (d) 1  =
7 8 7 3 8 93
Division of a Whole Number by a Fraction

To divide a whole number by a fraction, multiply the given whole number by the reciprocal
of the fraction (divisor). Reduce the fraction to its lowest terms, if possible.
1
Example 27: Divide 16 by .
4
1
Solution: 16 ÷
4
1 4
The reciprocal of the divisor is .
4 1
1 4 1
So, 16 ÷ = 16 × = 16 × 4 = 64 So, 16  = 64.
4 1 4
Division of a Fraction by a Whole Number

To divide a fraction by a whole number, multiply the given fraction by the reciprocal of the whole
number (divisor). Reduce the fraction to its lowest terms, if possible.
4
Example 28: Divide 3 by 15.
7
4 (3  7) + 4 15 25 15
Solution: 3 ÷ 15 = ÷ = ÷
7 7 1 7 1
5
25 1 1 5  1 5
=  (The reciprocal of 15 is )= =
7 15 15 7  3 21
3
4 5
So, 3  15 = .
7 21

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