1. Formula: amount of change
Math-8 NOTES
DATE: ______/_______/_______
What: percent of change
Why: To calculate the percent of increase/decrease for various real-life situations.
NAME:
Vocabulary:
Percent of Change– tells how much an amount has increased or
__________________________ in relation to the original amount.
Formula: amount of change
original amount
Step One: Subtract to find the amount of change.
Step Two: Write as a ratio with the original amount as the
denominator.
Step Three: Divide to find decimal and change to a % (“take the top
number, divide by the bottom #!”) .
Examples:
In 1962, the price of a McDonald’s hamburger was $ It is now $ Calculate the percent of increase.
The price of movie tickets in 1962 was $ Now, it is $ Calculate the percent of increase.

2. Sara’s hair was about 14 inches long in the back
Sara’s hair was about 14 inches long in the back. After her haircut, her hair is now about 4 inches long in the back. Calculate the percent of decrease.
In 2008, Ms. Dyson bought a palm tree that was about 24 inches tall. It has now grown to about 38 inches tall. Calculate the percent of increase.
In 1962, the University of Pennsylvania charged $1,250 per year for tuition. Now, the tuition is $42,098 per year. Holy Cow! Calculate the percent of increase.
Justin weighed 250 lbs. two years ago. He began a strict diet and now weighs 190 lbs. Way to go Justin! Calculate the percent of decrease.

3. Formula: amount of change
Math-8 Practice
“percent of change”
DATE: ______/_______/_______
NAME:___________________________________
Formula: amount of change
original amount 1) 2) 3) 4) 5) 6) 7) 8)