My question is: Ava planted 9 apple trees in her backyard. That's 3 more than Lily planted in her backyard. How many apple trees did they plant in their backyards collectively? Your thoughts:
Lily planted 9 - 3 = 6 apple trees in her backyard. They planted 9 + 6 = 15 apple trees in their backyards collectively. The final answer: 15.