conversations.from: human
conversations.value: Find the answer to this math problem: Mr. Doré bought $140 worth of pants, a $43 shirt and a $15 tie. He pays with a $200 bill. How much will the saleswoman give him back?
conversations.from: assistant
conversations.value: The total expenses are $140 + $43 + $15 = $198.
  Mr. Doré paid $200, so the saleswoman must give him $200 - $198 = $2 back.