Question

Write each of the following as decimals:
(i) $40\frac{2}{5}$
(ii) $39\frac{2}{10}$
(iii) $4\frac{3}{5}$
(iv) $25\frac{1}{2}$

Answer 1

(i) $40\frac{2}{5}=40+\frac{2}{5}$
To write in decimal, we need to make the denominator $10$ or $100$ or $1000$ by multiplying it by a number. But, to maintain the value of the fraction, we should also multiply the numerator by the same number. Thus, we get

$=40+\frac{2\times 2}{5\times 2}$

$=40+\frac{4}{10}$

$=40+0.4$

$=40.4$

Thus, $40\frac{2}{5}=40.4$
(ii) $39\frac{2}{10}=39+\frac{2}{10}$

Here, the denominator is already $10$.

$=39+0.2$

$=39.2$

Thus, $39\frac{2}{10}=39.2$
(iii) $4\frac{3}{5}=4+\frac{3}{5}$

$=4+\frac{3\times 2}{5\times 2}$

$=4+\frac{6}{10}$

$=4+0.6$

$=4.6$

Thus, $4\frac{3}{5}=4.6$
(iv) $25\frac{1}{2}=25+\frac{1}{2}$

$=25+\frac{1\times 5}{2\times 5}$

$=25+\frac{5}{10}$

$=25+0.5$

$=25.5$

Thus,$25\frac{1}{2}=25.5$