1. Percentages As Decimals. 67% = 0.67 43% = 0.43 6% = 0.06 89% = 0.89

2. From Percentage To Decimal. To turn any percentage into a decimal look at the following: 66% = 66 100 To divide by 100 move the point 2 places to the left. =0.66 Now change the percentages below to decimals. (a)87%= 87 100 =0.87 24% = 24 100 =0.24(b) (c) 12% = 12 100 =0.12 (d)4 % = 4 100 =0.04

3. Finding A Percentage Using A Decimal. We are now going to use decimals to calculate the following percentages. (a) Calculate 47% of £670 Solution 47% of £670 = The word “of” in maths means “multiply”. 47% x £670 = Change 47% to a decimal. 0.47 x £670 = Now calculate the sum. £314.90

4. (b) Calculate 7% of 2345 people. Solution 7% of 2345 = The word “of” in maths means “multiply”. 7% x 2345 = Change 7% to a decimal. 0.07 x 2345 = Now calculate the sum. 164.15 164 rounded to the nearest person.

5. (c) In a sale 12½% is taken off a ski jacket whose normal price is £145. Find the sale price. Solution 12½% of 145 = 12½% x 145 = 0.125 x 145 =£18.125 £18.13 rounded to the nearest 1 pence. Cost of ski jacket: £145 - £18.13 = £126.87

6. Making Calculations Faster. In the last problem 12½ % was taken off the price. What percentage of the price did the customer pay? 100 – 12½ =87½ % Now calculate 87½% of £145 0.875 x £145 =£126.875 £126.88 rounded to the nearest 1p. Why is there 1p difference in price?

7. What Goes In The Box? Calculate: (1) 45% of 325 days. (2) 86% of 4567 girls. (3) 19% of 674 fish. (4) The sale price of a dress at £245 with 17% off. (5) The sale price of a car at £5670 with 25½% off. 0.45 x 325 = 146 days 0.86 x 4567 = 3928 girls. 0.19 x 674 = 128 fish. 0.83 x 245 = £203.35 0.745 x 5670 = £4224.15