conversations.from: human
conversations.value: 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?
  Solve this problem.
conversations.from: assistant
conversations.value: 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.