conversations.from: human
conversations.value: Cheryl ate 7 m&m's after lunch. She ate 5 m&m's after dinner, and she gave some to her sister. If Cheryl had 25 m&m's at the beginning, how many did she give to her sister?
  Solve this problem.
conversations.from: assistant
conversations.value: Cheryl at 7 + 5 = 12 m&m's
  She gave 25 - 12 = 13 m&m's to her sister.