conversations.from: human
conversations.value: Explain how to solve this math problem: Derek has $960 to buy his books for the semester. He spends half of that on his textbooks, and he spends a quarter of what is left on his school supplies. What is the amount of money Derek has left?
conversations.from: assistant
conversations.value: Amount spent on textbooks is 960/2 = 480 dollars.
  Amount spent on school supplies is 480/4 = 120 dollars.
  Amount Derek has left 960-480-120 = 360 dollars.