1. Percent Change: Percent Increase / Percent Decrease
Objective:
Learn to solve problems involving percent increase and percent decrease.

2. Gaby went to Kalas and wanted to buy a really cool red dress
Gaby went to Kalas and wanted to buy a really cool red dress. The dress was on sale 25% off. If the original price of the dress was $165 dollars, how much will the price be reduced?
When a price or number changes, you can use the following formula to describe the increase or decrease.
Percent change = amount of change
original amount

3. If we use the formula for example 1:
Percent change = amount of change
original amount
So you have to substitute the values….
25 = X
$165
100 X = (when dividing by 100,
move the decimal point places to the left.)
X =

4. Example 2: Find the percent increase or decrease,
if 15 is increased to 20.
Percent change = amount of change
original amount
P = 5
15 P =
P = %
To find the amount of change you must subtract the original amount and the new amount.

5. Your Examples:
1. Find the percent increase or decrease (the percent change) if 96 is decreased to 72.
Percent change = amount of change
original amount
2. Find the amount of increase or decrease or the ( amount of change) if 75 is increased by 60%.

6. Homework: Find each Percent change or percent increase or decrease.
Find the amount of change or amount increase or decrease.
125 is decreased to 2.
360 is increased to 361.
84 is decreased to 28.
615 is decreased to 450.
460 is increased to 500.
58 is increased by 72%.
28 is increased by 150%.
506 is decreased by 57%.
4 is increased by 12%.
48 is increased by 35%.