Fraction of an amount

Topic summary

To find a fraction of an amount, divide the amount by the denominator (bottom) of the fraction, then multiply by the numerator (top).

Unit fractions

\[\frac{1}{5} \times 40 = 40 \div 5 = 8\]

Non-unit fractions

\[\frac{2}{7} \times 21 = (21 \div 7) \times 2 = 3 \times 2 = 6\]

The word ‘of’

If you see the word ‘of’ in a question, it means the same as times.

\[\frac{3}{4} \text{ of } 20 = \frac{3}{4} \times 20 = 15\]