1. Percent Increase/Decrease

2. Percent of change = amount of change (difference) original amount (what we started with) Percent of increase = original amount goes up Percent of decrease = original amount goes down

3. Find the percent of increase or decrease from 20 to 24. % of change = amount of change = 24 – 20 = 4 original amount = 20 Set up proportion: 4 = X 20 100 Cross multiply: 20(X) = 4(100) 20X = 400 Divide to get the variable alone: 20X = 400 X = 20% increase

4. Find the percent of increase or decrease from $49.60 to $38.10. % of change = amount of change = $49.60 – $38.10 = $11.50 original amount = $49.60 Set up proportion: 11.50 = X 49.60 100 Cross multiply: 49.60(X) = 11.50(100) 49.60X = 1150 Divide to get the variable alone: 49.60X = 1150 X = 23% decrease

5. Find the percent of increase or decrease from 33 to 47 % of change = amount of change = 47 – 33 = 14 original amount = 33 Set up proportion: 14 = X 33 100 Cross multiply: 33(X) = 14(100) 33X = 1400 Divide to get the variable alone: 33X = 1400 X = 42% increase

6. Find the percent of increase or decrease from 58 to 53 % of change = amount of change = 58 – 53 = 5 original amount = 58 Set up proportion: 5 = X 58 100 Cross multiply: 58(X) = 5(100) 58X = 500 Divide to get the variable alone: 58X = 500 X = 8.6% decrease

7. YOUR TURN 1)Find the percent of increase or decrease from 8 to 4. 4 = X 8 100 8(X) = 4(100) 8X = 400 X = 50% decrease 1)2) Find the percent of increase or decrease from 79 to 94. 15 = X 79 100 79(X) = 15(100) 79X = 1500 X = 18.9% increase

8. YOUR TURN 1)Find the percent of increase or decrease from 174 miles to 135.9 miles. 38.1 = X 174 100 174(X) = 38.1(100) 174X = 3810 X = 21.9% decrease 1)2) Find the percent of increase or decrease from 55 grams to 70 grams. 15 = X 55 100 55(X) = 15(100) 55X = 1500 X = 27.3% increase