Finding a percentage of an amount without

Finding a percentage of an amount…. . without a calculator!

No more of these …. .

or these…. .

100% is…… the whole amount

Start by finding 10% Easy enough to do because 10 x 10% = 100%

So to find 10%. . . just divide by 10

Find 10% of 48 = 48 ÷ 10 = 4. 8

Find 10% of 590 = 590 ÷ 10 = 59

Your turn u 10% u 10% of of of 58 = 58÷ 10 = 5. 8 50 = 50÷ 10 = 5 140 = 140÷ 10 = 14 5. 4 = 5. 4÷ 10 = 0. 54 21. 4 = 21. 4÷ 10 = 2. 14

You must set our your answers correctly Like mine that means

Exam question In a sale a pair of trainers which cost £ 48 originally are reduced by 10%. Find the ‘sale price’. 10% of £ 48 = 48÷ 10 = £ 4. 80 Sale price = £ 48 - £ 4. 80 = £ 43. 20

One for you I get a 10% discount if I use my Hull City credit card in the shop. How much would I pay if I used my card to buy a shirt priced at £ 38. 60?

and the answer…. . 10% of £ 38. 60 = £ 38. 60 ÷ 10 = £ 3. 86 ‘card price’ = £ 38. 60 - £ 3. 86 = £ 34. 74

Finding 20% u First find 10% (by dividing by 10) u Then ‘double it’ (2 x 10% = 20%) u Do NOT just divide by 20 – it will not work

Example - Find 20% of £ 56 10% of £ 56 = £ 56 ÷ 10 = £ 5. 60 20% of £ 56 = 2 x £ 5. 60 = £ 11. 20

If you can find 10% then…. u 20% u 30% u 40% u 70% = = 2 3 4 7 x 10% and so on…

Find 30% of 85 kg 10% of 85 kg = 85 ÷ 10 = 8. 5 kg 30% of 85 kg = 3 x 8. 5 = 25. 5 kg

5% = 10% ÷ 2

2. 5% = 5% ÷ 2

Find 35% of 82 10 % of 82 = 82 ÷ 10 = 8. 2 30% of 82 = 3 x 8. 2 = 24. 6 5% of 82 = 8. 2 ÷ 2 = 4. 1 35% of 82 = 24. 6 + 4. 1 = 28. 7 (30% + 5% = 35%)

Exam question V. A. T. is charged at 10% of £ 12000 = 17. 5% on new cars. £ 1200 If a car is purchased 5% of £ 12000 = for £ 12000, £ 600 calculate the V. A. T. 2. 5% of £ 12000 = £ 300 17. 5% of £ 12000 = 1200+600 + 300 = £ 2100