Reverse Percentages Notes

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Reverse Percentages

If we have increased our value by a percentage, we add that percentage to 100. We then divide by the new number and multiply by 100.

Example

e.g. A laptop has increased in value by 8%, it now costs £368. How much did it cost before?

Working:

(÷108) 368 = 108% (÷108)

(x100) 3.4074... = 1% (x100)

340.407 = 100%

£340.74

If we have decreased our value, we subtract that percentage from 100. We then divide by the new percentage and multiply by 100.

Example

e.g. A top has been reduced by 15% to £21.25. What did it cost before?

(÷85) 21.25 = 85% (÷85)

(x100) 0.25 = 1% (x100)

25 = 100%

£25

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