1. 1 Percent Proportion

2. 2 Percent Means ‘of a hundred’

3. 3 The Percent Proportion(s) You will use a proportion to solve most percent problems. Remember: the percent will always be related to a hundred.

4. 4 The Percent Proportion(s) is of % 100 = The percent % is always over 100. ‘is’ is the number with the word ‘is’ ‘of’ is the number with the word ‘of’ 100 is always on the bottom. This proportion can be used when dealing with simple percent statements such as: “What is 10% of 100?” “10 is what percent of 100?” “10 is 10% of what number?”

5. 5 What is 85% of 20? Use the proportion. is of % 100 = x 20 85 100 = 20 x 5 = 100 What x 5 = 85? x = 17 17 is 85% of 20

6. 6 25% of what number is 400? Use the proportion. is of % 100 = 400 x 25 100 = 25 x 16 = 400. 100 x 16 = 1600. x = 1600 25% of 1600 is 400

7. 7 16 is what percent of 20? Use the proportion. is of % 100 = 16 20 x 100 = 20 x 5 = 100. 16 x 5 = 80 x = 80 16 is 80% of 20

8. 8 What is 40% of 25? What percent of 20 is 14? (or 14 is what percent of 20?) 50% of what number is 44?

9. 9 What is 40% of 25? Use the proportion. is of % 100 = x 25 40 100 = 25 x 4 = 100. What x 4 = 40? x = 10 10 is 40% of 25

10. 10 What percent of 20 is 14? Use the proportion. is of % 100 = 14 20 x 100 = 20 x 5 = 100. 14 x 5 = 70 x = 70% 70% of 20 is 14

11. 11 50% of what number is 44? Use the proportion. is of % 100 = 44 x 50 100 = Cant easily do 44 x what is 50….but what can you do? x = 88 44 is one half of 88

12. 12 We will work on cross multiplication next class. When all else fails, use cross multiplication.