Working back to old price
You learn to work out the old price of an item when you know the discount and the sale price.
How to work it out
- The sale price is less than 100%: after 25% discount you pay 75%.
- Divide the new price by that percentage for 1%, and do times 100 for the old price.
75
25
100
60
20
80
New price £60 after 25% discount
- First write down what you know: after 25% off you pay 75%, and that is £60.
- Divide by 3 for 25%: 60 ÷ 3 = 20.
- Multiply by 4 for 100%: 4 × 20 = 80.
- The old price was £80.
75
25
100
60
20
80
More examples
New price £72 after 20% discount
- First write down what you know: after 20% off you pay 80%, and that is £72.
- Divide by 4 for 20%: 72 ÷ 4 = 18.
- Multiply by 5 for 100%: 5 × 18 = 90.
- The old price was £90.
80
20
100
72
18
90
New price £45 after 10% discount
- First write down what you know: after 10% off you pay 90%, and that is £45.
- Divide by 9 for 10%: 45 ÷ 9 = 5.
- Multiply by 10 for 100%: 10 × 5 = 50.
- The old price was £50.
90
10
100
45
5
50