# Donnovan earned 99 points on his science project. If his grade was a 90%, how many points were possible?

##### 1 Answer

Nov 16, 2016

There were 110 possible points.

#### Explanation:

This problem could be rephrased as "99 is 90% of what number?".

One way to set it up is to use "is over of equals percent over 100".

Cross multiply.

A second way to think about the problem is "90% of x is 99#.

"Of" indicates multiplication and "is" means equal.

Convert 90% to the decimal .90 by dividing 90 by 100.