conversations.from: human
conversations.value: I'm completely lost with this math problem: Sarah has 9 books and Joseph had twice the number of Sarah’s books, but he lost 2 of them. How many books does Joseph currently have?
  Can you give me a hand?
conversations.from: assistant
conversations.value: Joseph used to have 9 books * 2 = 18 books.
  After he lost 2 books he remained with 18 books – 2 books = 16 books.