Change Expressed as a

PercentYou will:

• Find percent change

Warm Up

Percent Change: Expresses an amount of change as a percent of an

original amount% off, % markup, % discount

Percent Increase:

Percent Decrease:

The new amount is greater than the original amount

(Mark up)

The new amount is less than the original (Discount)

Percent Change:The ratio of the amount of change to the original amount.

Percent Change (p%) =

a) A coat is on sale. The original price of the coat is $82. The sale price is $74.50. What is the discount expressed as a percent change?

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?

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?

Problem 1

a) 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?

Problem 2

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

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?

Problem 2

Determine whether each percent change is an increase or decrease.

Then find the percent change. Round to the nearest degree.

a)Original amount: 7.5 b) Original amount: 2008

New amount: 9.5 New amount: 1975

Problem 3

Textbook Page 148; # 2 – 16 Even, #17

Homework Assignment

2) 61%4) a. decrease, b. decrease, c. increase6) Increase involves an increase of the original amount and decrease involved a decrease of the original amount8) Decrease 33%10) Increase 27%12) Decrease 2%14) Increase 10%16) 9%17) 55%

Homework Answers