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? Think carefully first, then make a decision:
Each school has 4 + 5 = 9 classes. So, there are a total of 9 x 2 = 18 classes for the 2 schools. Therefore, the public official donates a total of 18 x 5 = 90 soccer balls. So, the answer is 90.