1. Bell Quiz

2. Objectives Find the percent of increase or decrease of a number

3. Percent of Change The percent of change is the ratio of the amount of change in a quantity to the original amount, expressed as a percent. The percent of change can be a percent of increase or a percent of decrease.

4. Example 1 Finding the Percent of Increase or Decrease Find the percent of change. Number of U.S. airports in 1985: 15,161 Number of U.S. airports in 2005: 19,854

5. Example 2 Finding the Percent of Increase or Decrease Find the percent of change. Number of taxicabs in the U.S. in 2001: 31,800 Number of taxicabs in the U.S. in 2002: 30,800

6. Lesson Practice 1 Find the percent of change. January 2006 salary: $600/week January 2007 salary: $630/week

7. Lesson Practice 2 Find the percent of change. Number of words in the first draft of an essay: 1032 Number of words in the final draft of an essay: 774

8. Markup/Discount A markup results when a percent of increase is applied to a cost. A discount results when a percent of decrease is applied to a cost.

9. Example 3 Finding Markups and Discounts A music store marks up the price of CDs they purchases at $9.00 each by 70%. What is the markup and new price of each CD?

10. Example 4 Finding Markups and Discounts A bookstore is having a sale of 40% off all items. What is the discount and new price of a book that originally cost $12?

11. Lesson Practice 3 A shoe store marks up the price of a pair of boots that cost the store $44.00 by 45%. What is the markup and new price of the pair of boots?

12. Lesson Practice 4 A real estate agency is selling a house at 22% off the original cost of $344,000. What is the discount and the new price of the house?

13. Example 5 Application: Raising Funds In 2006, the 100 Mile BEADS Walkathon for Education, Advancements, Development, and Success raised $36,000 for girls in Africa. The organizers hope to raise $100,000 in 2007. What will be the percent of increase in the amount raised?

14. Lesson Practice 5 A weightlifter can lift 90 pounds. After six months he can lift 125 pounds. What is the percent of increase in the amount of weight he can lift?

15. Lesson Practice 6 Binders that originally sold for $4.95 each are now selling for $3.87 each. What is the percent of decrease in the price of the binders?