Page 138 - Start Up Mathematics_6

Example 15: Write fractions for the shaded part and pair up the equivalent fractions from the two
rows.

(a) (b) (c) (d) (e)

(i) (ii) (iii) (iv) (v) (NCERT)

Solution: Writing the shaded part of each row as fractions in the simplest form, we get

1 1 4 2 3 1 2 1 3 3
Row 1 2 = 2 6 = 3 9 = 3 8 = 4 4 = 4

(a) (b) (c) (d) (e)

6 1 4 1 12 3 8 2 4 1
Row 2 18 = 3 8 = 2 16 = 4 12 = 3 16 = 4

(i) (ii) (iii) (iv) (v)

The pairs representing equivalent fractions are:

(a) (ii), (b) (iv), (c) (i), (d) (v), (e) (iii)
Example 16: Replace in each of the following by the correct number:

2 6 2
(a) = (b) =
7 10 5

Solution: (a) We observe the numerators of the given fractions. Since 6 ÷ 2 = 3, we multiply
2
both the numerator and the denominator of by 3.
7

2 2 × 3 6
Now, LHS = = = . Hence 21 is the correct number.
7 7 × 3 21
Aliter

Let x be the denominator of the equivalent fraction whose numerator is 6.
2 6 Reason It Out!
∴ =
7 x a a
⇒ 2 × x = 7 × 6 If = c , what must be true?
b
7 × 6
⇒ x = = 21
2

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