Percentages of Quantities Remember A percentage is simply

Percentages of Quantities Remember: A percentage is simply a fraction out of 100. 23% 56% 84% 0. 23 0. 56 0. 84

Percentages of Quantities Remember: A percentage is simply a fraction out of 100. Calculating percentages using a calculator Example 1: Calculate 23% of £ 56 23 of 56 100 0. 23 x 56 5 6 x 0. 2 3 £ 12. 88 =

Not to be taken down! 14% of 90 = 0. 14 x 90 3% of 62 = 0. 03 x 62 67% of 92 = 0. 67 x 92

Percentages of Quantities Use your calculator to calculate the following. Q 1: Calculate 54% of £ 89 £ 48. 06 Q 3: Calculate 84% of 350 g 294 g Q 5: Calculate 71% of 28 l 19. 88 l Q 7: Calculate 7% of £ 750 £ 52. 50 Q 2: Calculate 17% of 33 m 5. 61 m Q 4: Calculate 24% of $450 $108 Q 6: Calculate 43% of 16 kg 6. 88 kg Q 8: Calculate 39% of 7. 2 km 2. 808 km

Percentage increase using a calculator Example 1: Increase $60 by 32% We need to find 32% of 60, then add it to 60 60 + 0. 32 x 60 = 60 x 1 + 0. 32 x 60 Which combines to 60 x 1. 32 6 0 x 1. 3 2 = $79. 20

Not to be taken down! Increase 90 by 14% = 1. 14 x 90 Increase 62 by 3% = 1. 03 x 62 Increase 92 by 67% = 1. 67 x 92

Percentage Increases Use your calculator to calculate the following. Q 1: Increase 80 by 3% 82. 4 Q 3: Increase 320 by 14% 364. 8 Q 5: Increase 94 by 11% 104. 34 Q 2: Increase 54 by 13% 61. 02 Q 4: Increase 640 by 42% 908. 8 Q 6: Increase 48 by 16% 55. 68

Percentage decrease using a calculator Example 1: Decrease $60 by 32% We need to find 32% of 60, then take it away from 60 60 - 0. 32 x 60 = 60 x 1 - 0. 32 x 60 Which combines to 60 x 0. 68 6 0 x 0. 6 8 = 40. 8 1 – 0. 32 = 0. 68

Not to be taken down! Decrease 90 by 14% = 0. 86 x 90 Decrease 62 by 3% = 0. 97 x 62 Decrease 92 by 67% = 0. 33 x 92

Percentage Decreases Use your calculator to calculate the following. Q 1: Decrease 80 by 3% 77. 6 Q 3: Decrease 320 by 14% 275. 2 Q 5: Decrease 94 by 11% 83. 66 Q 2: Decrease 54 by 13% 46. 98 Q 4: Decrease 640 by 42% 371. 2 Q 6: Decrease 48 by 16% 40. 32

Repeated Percentage Change $40 000 is invested at 5% per annum for 10 years. How much will the investment be worth after 10 years? We need to multiply 40 000 by 1. 05 ten times! 40 000 x 1. 0510 = $65155. 79 This will allow you to do the power of 10

$60 000 is invested at 12% per annum for 5 years. How much will the investment be worth after 5 years? $105740. 50 A car worth $24 000 depreciates at 15% per annum for 6 years. How much will the car be worth after 6 years? $9051. 59