1. Change Expressed as a Percent
You will:
Find percent change

2. Warm Up

3. % off, % markup, % discount
Percent Change:
Expresses an amount of change as a percent of an original amount
% off, % markup, % discount
Percent Increase:
The new amount is greater than the original amount
(Mark up)
Percent Decrease:
The new amount is less than the original
(Discount)

4. Percent Change:
The ratio of the amount of change to the original amount. Percent Change (p%) = 𝑎𝑚𝑜𝑢𝑛𝑡 𝑜𝑓 𝑖𝑛𝑐𝑟𝑒𝑎𝑠𝑒 𝑜𝑟 𝑑𝑒𝑐𝑟𝑒𝑎𝑠𝑒 𝑜𝑟𝑖𝑔𝑖𝑛𝑎𝑙 𝑎𝑚𝑜𝑢𝑛𝑡

5. Problem 1
A coat is on sale. The original price of the coat is $82. The sale price is $ What is the discount expressed as a percent change?

6. Problem 1
b) The average monthly precipitation for Chicago, Illinois, peaks in June at 4.1 inches. The average monthly precipitation in December is 2.8 inches. What is the percent change from June to December?

7. Problem 1
c) In 1990, the price of a gallon of unleaded gas was $1.37. In 1998 it was $1.02 per gallon. What is the percent of change? Is it an increase or decrease?

8. Problem 2
A store buys an electric guitar for $295. The store then marks up the price of the guitar to $340. What is the markup expressed as a percent change?

9. Problem 2
In one year, the toll charge for the Lincoln Tunnel rose from $8 to $12. What was the percent change?

10. Problem 2
c) Last year, an athlete’s average time to run a mile was 6 minutes 13 seconds. This year, the athlete’s average time is 6 minutes 5 seconds. What is the percent change? Does the percent change represent an increase or decrease?

11. Problem 3
Determine whether each percent change is an increase or decrease. Then find the percent change. Round to the nearest degree.
Original amount: b) Original amount: 2008
New amount: New amount: 1975

12. Textbook Page 148; # 2 – 16 Even, #17
Homework Assignment
Textbook Page 148; # 2 – 16 Even, #17

13. Homework Answers 61% a. decrease, b. decrease, c. increase
6) Increase involves an increase of the original amount and decrease involved a decrease of the original amount
8) Decrease 33%
10) Increase 27%
12) Decrease 2%
14) Increase 10%
16) 9%
17) 55%