Fractions, decimals & percentages
Fractions of a quantity
A fraction can be used as an operator to find part of an amount. To find a fraction of a number, divide by the denominator, then multiply by the numerator.
The method
1. Divide the amount by the denominator (the bottom number). 2. Multiply the result by the numerator (the top number).
Worked examples
Finding a fraction of an amount
- Find 3/4 of 24.
- Divide by 4: 24 ÷ 4 = 6.
- Multiply by 3: 6 × 3 = 18.
Answer: 3/4 of 24 = 18
Finding the whole from a part
- One quarter of a number is 8.
- The whole is made of 4 quarters, so multiply by 4: 8 × 4.
Answer: The number is 32.
Where you see this in real life
- Working out a half-price sale: half of $20 is $10.
- Finding when half-time is in an 80-minute game.
- Sharing part of your pocket money to a charity.
Key words
- Numerator
- The top number of a fraction — it tells you how many parts you have.
- Denominator
- The bottom number of a fraction — it tells you how many equal parts the whole is split into.
- Operator
- A fraction used to find a part of an amount.