Question

A student solved this problem by working backwards. Joani has some stuffed animals. She has 2 times as many as Lily. Lily has 6 stuffed animals. Joanie gave 2 away and bought 4 more. How many stuffed animals does Joani have now? Students's solution: Lily has 6 stuffed animals, so Joani had 6 × 2 to begin with. So Joani had 12 stuffed animals. She gave away 2, so 12 – 2 = 10. She bought 4, so 10 + 4 = 14. So Joani has 14 stuffed animals. Here is another problem that can also be solved by working backwards. Wyatt has 3 times as many baseballs as golf balls. He has 5 fewer tennis balls than baseballs. Wyatt has 4 golf balls. How many tennis balls does Wyatt have?

Answer 1

3x4=12 gives him 12 baseballs. he has 5 fewer tennis balls than base balls so you subtract 5 from 12 and you get 7 tennis balls.