A public official wants to donate 5 new soccer balls per each class in two schools. Each school has 4 elementary school classes and 5 middle school classes.  How many soccer balls would the public official donate in all?
Each school has 4 + 5 = <<4+5=9>>9 classes.
So, there are a total of 9 x 2 = <<9*2=18>>18 classes for the 2 schools.
Therefore, the public official donates a total of 18 x 5 = <<18*5=90>>90 soccer balls.
#### 90