1. Percent of Change

2. How much did a gallon of milk cost in the 1950’s?
What happens when you keep sharpening your pencil?
What if you get a raise in your allowance?

3. Percent of Change:
Compares the amount of change to the ORIGINAL amount!

4. Percent of Increase:
An increase from the ORIGINAL amount
Ex) The cost of milk in the 1950’s compared to today’s cost.

5. Percent of Decrease:
A decrease from the ORIGINAL amount
Ex) What happens to your pencil when you keep sharpening it?

6. Amount of Change =
The difference between the ORIGINAL amount and the NEW amount.
Life expectancy in 1900 was 45 years old; Life expectancy in 2012 is 78 years old. What is the amount of change?
78 – 45 = 33

7. Percent of Change Proportion:
SUBTRACT!!!
Amount
of Change % =
100
ORIGINAL
Amount
78 – 45 = 33

8. Steps for Finding Percent of Change:
Determine whether the amount is INCREASING or DECREASING from the ORIGINAL amount.

9. Steps for Finding Percent of Change:
2. Find the amount of CHANGE.
SUBTRACT!!!
3. Set-up the Percent Proportion. %
Amount of Change =
100
Original Amount

10. Example 1:
An 8 ft. tree grows to be 10 ft. tall in the last year. What is the tree’s percent of change?
Increase or Decrease? 25
2 ft %
Amount of Change =
100
8 ft
Original Amount

11. Example 2:
A pair of jeans was originally priced at $40, but is on sale for $36. What is the percent of change?
Increase or Decrease? $4 10 %
Amount of Change =
100
$40
Original Amount