Jill bought 5 packs of red bouncy balls and 4 packs of yellow bouncy balls. Each package contained 18 bouncy balls. How many more red bouncy balls than yellow bouncy balls did Jill buy? Think carefully first, then make a decision:
Jill bought 5 packs * 18 red balls = 90 red balls. Jill bought 4 packs * 18 yellow balls = 72 red balls. Jill had 90 red 72 yellow = 18 more red balls. So, the answer is 18.