1. Percentages 17/10/2015 1 17 October 2015

2. Contents Converting between Fractions Decimals and Percentages Finding a Percentage 17/10/2015 2

3. Converting between F, D & P Converting a percentage to a fraction 40% means 40 out of every 100 Don’t forget to cancel down, if possible

4. Converting between F, D & P Converting a percentage to a decimal 67% means i.e. 67  100 Remember  by 100 ? HTU 67 6 7 So, 67% = 0.67

5. Converting between F, D & P Converting a decimal to a percentage Reverse the process i.e. X by 100 HTU 043 4 3 So, 0.43 = 43%

6. Converting between F, D & P Converting a fraction to a percentage Convert to a decimal first then to a percentage i.e. Then, change to a percentage, x by 100 So, = 0.6 = 60%

7. Finding a Percentage - Remember, 10% = To find we  by 10 Also, 1% = And, to find we  by 100 Without a Calculator

8. Finding a Percentage - Use these facts to find any percentage i.e. Find 32% of 240AED 10% = 24AED and 1% = 2.40AED So, 30% = 3 x 24AED = 72AED and 2% = 2 x 2.40AED = 4.80AED 32% = 72.00AED + 4.80 = 76.80AED Without a Calculator

9. Finding a Percentage - 55% of 120 children at the theatre were boys, how many were boys ? 10% = 12 and 1% = 1.2 So, 50% = 5 x 12 = 60 and 5% = 5 x 1.2 = 6 55% = 60 + 6 = 66 boys (5% can also be found by using ½ of 10%) Without a Calculator

10. Finding a Percentage - Change percentage to a decimal first eg. Find 28% of 690 28% = 0.28 and “of” means multiply So 28% of 690 is 0.28 x 690 Type into your calculator Answer = 193.2 With a Calculator

11. Finding a Percentage - Another example, find 17.5% of £250 So, 0.175 x 250 Type into calculator Answer = £43.75 Find 32.5% of 1200 … 0.325 x 1200 = With a Calculator 390

12. Writing as a Percentage What percentage of cars are Green ? 22 out of 122 were green, so Change to a decimal Then convert to a percentage Car Park Survey ColourFrequency Green22 Silver43 Black57 =18%