Fractions

A fraction is part of a whole split into equal parts. The bottom number (denominator) says how many equal parts; the top number (numerator) says how many we have.

Key facts

  • The parts must be equal.
  • Denominator: how many equal parts. Numerator: how many parts we have.
  • To find a fraction of an amount, divide by the bottom and multiply by the top.
  • The bigger the denominator, the smaller each part.

Worked examples

Example 1

What fraction of the shape is shaded?

  1. There are 8 equal parts.
  2. 3 are shaded.
  3. So it’s 3/8.

Answer: 3/8

Example 2

Find 3/4 of 20.

  1. Find 1/4: divide by the bottom. 20 ÷ 4 = 5
  2. Find 3/4: multiply by the top. 5 × 3 = 15

Answer: 15