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Published byJasper Nash Modified over 8 years ago

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% Percentages % What does percent mean? ‘per cent’ means per hundred % means /100 So 50% means 50 out of 100

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To change a percentage to a fraction Percentages already are fractions: always fractions of 100: 20% means –Next step: simplify: 20 100 20 100 2 10 1515 ==

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50 100 20 100 1 100 2 100 4 100 15 100 6 100 80 100 5 100 70 100 28 100 35 100 90 100 64 100 22 100

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1212 1515 1 100 1 50 1 25 3 20 3 50 4545 1 20 7 10 7 25 7 20 9 10 16 25 11 50

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25% 10% 75% 40% 18% 45% 34% 30% 85% 8%16% 98% 96% 60% 95%

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You have 1p, 5p, 10p and 50p coins. What is the smallest number of these coins you need to make:

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How to find a % of an amount If it’s a simple percentage, use the fraction equivalent (eg for 50%, 25%, 10% use ½, ¼, 1 / 10 ) If it’s a combination of simple ones, work them out, then put them together (eg for 75% do 3 x 25%, or for 30% do 3 x 10%) If it’s more complex, split it into simple ones. (eg 37% = 3 x 10% + 7 x 1%)

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26% of £50 = 10% of £50 + 10% of £50 + 5% of £50 + 1% of £50 = £5 = £2.50 = £0.50 = £13

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Finding a percentage change – Method 1 To calculate a change in percentage, first work out the percentage change as an amount, then add it on (or take it off). RoundUp: Usually 800ml Adding on 25% of 800ml which is 200ml New Amount: 1000ml (or 1l)

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Finding a percentage change – Method 2 Write the final percentage as a decimal (eg for a 25% increase, 1.25, or a 30% decrease, 0.7), then multiply by the original amount. Drill: Usually £180 15% decrease leaves 85% or 0.85, so x 0.85 New Price: £153

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£16 £50 £68 £150 £300 £12 £37.50 £51 £112.50 £225 1234512345

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£62,000 £87 £93.50 £16.29 £96 £55,800 £78.30 £84.15 £14.66 (rounded down) £86.40 1234512345

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£62 £1000 £1.00 £12 £600 £49.60 £800 £0.80 £9.60 £480 1234512345

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84 96 48 56 50 126 144 72 84 75 1234512345

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