conversations.from: human
conversations.value: Dale is selling butterscotch candies to raise money for his club at school. He doesn't have the candies yet and is instead just taking orders. He started off with 100 total that he ordered and wanted to sell, but he ended up selling 150 butterscotch candies. Then he ordered 100 more. How many does Dale still need to sell to sell all of his candy?
conversations.from: assistant
conversations.value: Dale starts off selling 100 butterscotch candies that he ordered, but ends up selling 150, 100 - 150 = -50 candies.
  So Dale orders 100 more candies to make up for the deficit and to sell even more, -50 candies + 100 candies = 50 candies Dale has left and still needs to sell.