Example 1
Find 10% of £80.00.
- 10% means one tenth of the amount.
- Divide 80 by 10.
- 80 divided by 10 = 8
So: 10% of £80.00 is £8.00.
Back to National 3
Topic
Percentages
Percentages are used for discounts, prices, results, and comparing amounts. A percentage means out of 100, so 40% means 40 out of every 100.
Topic explanation
To find a simple percentage of an amount, use a friendly step. For 10%, divide by 10. For 50%, halve the amount. For 25%, divide by 4.
For a simple discount, find the percentage amount first, then subtract it from the price.
Always check whether the answer should be money, a number, or a percentage.
Quick methods
- 10%
- Divide by 10.
- 5%
- Find 10%, then halve it.
- 50%
- Divide by 2.
- 25%
- Divide by 4.
- Discount
- Find the saving, then subtract it.
Worked examples
Example 2
A jacket costs £45.00. It has 20% off. What is the sale price?
- First find 10% of £45.00: 45 divided by 10 = £4.50
- 20% is double 10%, so £4.50 × 2 = £9.00
- Take the discount away: £45.00 − £9.00 = £36.00
So: The sale price is £36.00.
Example 3
A jumper costs £40.00. It has 25% off. What is the sale price?
- 25% means one quarter.
- Find one quarter of £40.00: 40 divided by 4 = £10.00.
- Take the discount away: £40.00 − £10.00 = £30.00
So: The sale price is £30.00.