Percentages (GCSE)
Multiplier method, percentage change, percentage of an amount.
The multiplier method is the GCSE workhorse: a 12% increase = ×1.12; a 20% decrease = ×0.80. Repeated change compounds via repeated multiplication.
Worked examples
£240 + 15% = 240 × 1.15 = £276.
£500 − 12% = 500 × 0.88 = £440.
3% increase per year for 5 years on £1000: £1000 × 1.035 ≈ £1159.27.
Frequently asked questions
Find original from increased value?
Reverse percentage: divide by the multiplier. £276 was a 15% increase from £276 / 1.15 = £240.
VAT?
20% UK standard. Add: ×1.20; remove: ÷1.20. vatcalculator.uk handles it.