Page 75 - Math Skill - 4

Fractions 73

Let’s Attempt

Example 1: Write 4 equivalent fractions of 3 .
5
Solution: Given fraction = 3
5
Multiply the numerator and the denominator of the fraction by 2, 3, 4 and 5.

32× = 6 ; 33× = 9 ; 34× = 12 ; 35× = 15
52× 10 53× 15 54× 20 55× 25
6 9 12 15 3
Thus, , , and are 4 equivalent fractions of .
10 15 20 25 5
2
Example 2: Write an equivalent fraction of with numerator 8.
5
2 8
Solution: Let =
5 ?
8 ÷ 2 = 4 (Divide the bigger numerator by the smaller)
24× 8
= (Multiply both the numerator and denominator by 4)
54 20
×
Thus, the equivalent fraction of 2 is 8 .
5 20

Example 3: Write an equivalent fraction of 3 with denominator 21.
7
3 ?
Solution: Let =
7 21
21 ÷ 7 = 3 (Divide the bigger denominator by the smaller)

33× 9
= (Multiply both the numerator and denominator by 3)
×
73 21
9
3
Thus, the equivalent fraction of 7 is 21 . Fact-o-meter
Example 4: Are the following fractions equivalent? For a given fraction,
3 21 7 21 infinite (unlimited)
(a) 4 and 28 (b) 9 and 18 number of equivalent

Solution: (a) By cross multiplication, we get fractions can be
formed.
3 21
4 28 ⇒ 3 × 28 = 84 and 4 × 21 = 84
The products are equal.

Thus, 3 and 21 are equivalent fractions.
4 28

7 21
(b) ⇒ 7 × 18 = 126 and 9 × 21 = 189
9 18
The products are not equal.

Thus, 7 and 21 are not equivalent fractions.
9 18