Question: Mark had 10 pieces of fruit to eat in school this week. On Friday, he decided to keep 2 pieces of fruit for next week. He then brings the remaining 3 pieces of fruit to school for the day. How many pieces of fruit did Mark eat in the first four days of the week? Think carefully first, then make a decision:
Only 10 2 = 8 pieces of fruit were eaten this week. Subtracting Friday's snacks shows Mark ate 8 3 = 5 pieces of fruit in the first four days of the week. So the answer is 5.