1. Lesson 3.7- Percent of Change, pg. 160
Goals: To find percents of increase and decrease.
To solve problems involving percents of change.

2. Vocabulary
Percent of change: an increase or decrease expressed at a percent.
Percent of increase: the new number is greater than the original number.
Percent of decrease: the new number is less than the original number.

3. Percent of Change Formula
Percent of Change: difference in the amounts
original amount
Or Percent of change = New value-Original V
Original Value

4. Ex. 1: State whether each percent of change is a percent of decrease or increase. Then find the percent of change.
original: 32
new: 40
original: 20
new: 4

5. You TRY!!!!
original: 72
new: 36
original: 45
new: 50

6. Ex. 2: Find the missing value.
1. The price a used-book store pays to buy a book is $5. The store sells the book for 28% above the price that it pays for the book. What is the selling price of the $5 book?

7. Ex. 3: Find the total price of each item.
1. Software: $39.50
Sales tax: 6.5%
Compact disc: $15.99
sales tax: 5.75%

8. Ex. 4: Find the discounted price of each item.
jeans: $45.00
discount: 25%
book: $19.95
discount: 33%

9. Ex. 5: Find the final price of each
lamp: $120.00
discount: 20%
tax: 6%
camera: $58.00
discount: 25%
tax: 6.5%

10. Application
1. In 1987, the United States had 2 million active-duty military personnel. By 2000, there were only 1.4 million active-duty military personnel. What was the percent of decrease?

11. 2. In order for a food to marked “reduced fat,” it must have at least 25% less fat than the same full-fat food. If one ounce of reduced fat chips has 6 grams of fat, what is the least amount of fat in one ounce of regular chips?