conversations.from: human
conversations.value: Break down this math problem: A candle melts by 2 centimeters every hour that it burns. How many centimeters shorter will a candle be after burning from 1:00 PM to 5:00 PM?
conversations.from: assistant
conversations.value: The candle burns for 5 - 1 = 4 hours.
  Thus, the candle will be 2 * 4 = 8 centimeters shorter.