Practise finding percentages, percentage change and reverse-percentage problems with instant feedback.
What is 30% of £1,540?
Percentage calculations underpin almost every area of personal and business finance in the UK. From working out VAT on a supplier invoice to understanding how much a pay rise is really worth, the ability to move confidently between percentages, fractions and amounts is an essential everyday skill.
This drill covers three types of question that come up again and again in real life. The first is finding a percentage of an amount — for example, what is 17.5% of £840? This is the building block for all VAT, commission, and discount calculations. The second type is calculating percentage change — for example, if a salary rises from £32,000 to £35,200, what is the percentage increase? This skill is needed whenever you are comparing two values over time: house prices, inflation figures, sales growth, or pay rises. The third type is the reverse percentage — working backwards from a final price that already includes or excludes a percentage. For example, if a price after a 20% VAT uplift is £60, what was the original net price? This is crucial for bookkeepers and anyone checking supplier invoices.
All questions are randomly generated so you can practise as many as you like. Answers are checked to the nearest penny (tolerance ±1p), so you need to be accurate but not pixel-perfect. If you get a question wrong, the worked solution is shown immediately so you can see exactly where the calculation went.
A useful mental shortcut: to find 10% of anything, simply divide by 10. To find 1%, divide by 100. You can then build up any percentage from those two anchors — 17.5% is 10% + 5% + 2.5%, each half of the previous. For the reverse percentage, always divide by (1 + rate), never subtract the percentage directly — that is the single most common error.
Divide the percentage by 100, then multiply by the amount. For example, 20% of £450 = 0.20 × 450 = £90.
Subtract the old value from the new value, divide by the old value, multiply by 100. Example: (35,200 − 32,000) / 32,000 × 100 = 10%.
Divide the final price by (1 + rate). For a 20% increase the divisor is 1.20. So £60 ÷ 1.20 = £50.
Subtracting the percentage directly from the result. If a price rose 20% to £60, the wrong method is £60 × 0.20 = £12, giving £48. The correct method is £60 ÷ 1.20 = £50.
10% + 5% + 2.5%. For £240: 10% = £24, 5% = £12, 2.5% = £6. Total = £42. This was the old VAT rate in the UK before it rose to 20%.
A percentage point is an absolute difference between two percentages. If a rate rises from 3% to 5%, it rose by 2 percentage points but by 66.7% in relative terms. The distinction matters when reading economic news.
Divide the decrease by the original value and multiply by 100. For example, a price falls from £80 to £60: (80 − 60) / 80 × 100 = 25% decrease.
Yes — each question is randomly generated from a wide range of values and question types, so you can practise indefinitely without seeing the same question twice.
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