This GeoGebra file demonstrates percent change (increase and/or decrease). You may perform one, or two, percent changes. With this file you type in the percents you want to use. You may type decimals or fractions. The original number is the area of the blue rectangle. The changed number is the area of the red rectangle. Note the cumulative (compound) effect of two percent changes.

1. Two percent increases: If you do an increase of A%, followed by an increase of B%, is the overall percent change

less than

equal to, or

greater than

(A+B)% ?
2. Two percent decreases: If you do an decrease of A%, followed by an decrease of B%, is the overall percent change

less than

equal to, or

greater than

(A+B)% ?
3. Percent increase followed by a percent decrease: You start with a number. If you do an increase of A%, followed by an decrease of A%, the resulting amount will be:

less than

equal to, or

greater than

the original number ?
How do you get back to the original number
4. If you do an increase by 100%, what decrease will take you back to the original number?
5. If you do an increase by (the fraction) 1/3, what decrease will take you back to the original number?
6. If you do an increase by 50%, what decrease will take you back to the original number?