Math 7 · Unit 2, Lesson 5: Percent Increase and Decrease · Tile 3 of 3
Find the New Amount
Grow it or shrink it with one multiplier
When the percent change is given and the new amount is missing, it is the one-multiplier idea from Lessons 3 and 4.
A company grows
A company has 70 employees and grows by 10 percent. Ten percent of 70 is 7, so it has 77 employees. One step: 70 times 1.10 is 77. A 20 percent decrease would be times 0.80: 70 times 0.80 is 56.
A percent increase multiplies by more than 1; a percent decrease multiplies by less than 1.
Growing means times a number bigger than 1. Shrinking means times a number smaller than 1.
And backward, once
Sometimes the new amount is known and the original is missing. After a 10 percent increase, a company has 77 employees. Then 77 is 110 percent of the original. Ten percent of the original is 7, so the original is 70. Or divide: 77 divided by 1.10 is 70.
NC standards: NC.7.RP.3.