1. Percent of Change Decrease (Discount)

2. digital camera: $265, 30% markup
Warm-Up
Find the selling price for the item given the percent of markup.
digital camera: $265, 30% markup
100% =
50% =
25% =
10% =
5% =
1% =

3. Percent of Change
The percent that an amount changes from its original amounts is called the percent of change.
To find the percent of change, do the following:
Step 1 Subtract to find the amount of change.
Step 2 Write the ratio as a decimal.
Step 3 Write the decimal as a percent.
amount of change
original amount

4. Increase or Decrease
When the new amount is greater than the original, the percent of change is a percent of increase.
When the new amount is less than the original, the percent of change is called a percent of decrease.

5. Find the Percent of Change
Maria had 20 comic books. She gave some to her friend. Now she has 13 comic books. Find the percent of change. Is the percent of change an increase or decrease?
Step 1 The amount of change is 20 – 13 or 7.
Step 2 percent of change = =
= 0.35
Step 3 The decimal 0.35 written as a percent is 35%. So the percent of change is 35%.
Since the new number of members is less than the original, it is a percent of decrease.
amount of change
original amount 7 20

6. Original: 10 dogs New: 5 dogs
Example Problem
Find each percent of change. Round if necessary.
Original: 10 dogs New: 5 dogs

7. Original: 30 books New: 2 books
Example Problem
Find each percent of change. Round if necessary.
Original: 30 books New: 2 books

8. Find the Sales Price Calculate the Percent: 35% of $95 = 33.25
Academy is having a sale. A snowboard has an original price of $95. It is on sale for 35% off the original price. Find the sale price of the snowboard.
Calculate the Percent: 35% of $95 = 33.25
Subtract from Original: $95 – $33.25
Sales Price = $61.75
The sales price of the snowboard is $61.75.

9. Example Problem 100% = 50% = 25% = 10% = 5% = 1% =
Find the sale price of each item to the nearest cent.
CD: $14.50, 10% off
100% =
50% =
25% =
10% =
5% =
1% =

10. Example Problem 100% = 50% = 25% = 10% = 5% = 1% =
Find the sale price of each item to the nearest cent.
Sweater: $40.00, 25% off
100% =
50% =
25% =
10% =
5% =
1% =

11. Percent of Change: Decrease
Up Next…
Activity 1:
Percent of Change: Decrease