conversations.from: human
conversations.value: Can you give me some step-by-step instructions for this math problem: Joy has 30 pencils, and Colleen has 50 pencils. If they bought the pencils at $4 each at the store, how much more money did Colleen pay than Joy for her pencils?
conversations.from: assistant
conversations.value: The number of pencils that Colleen has more than Joy is 50-30 = 20 pencils.
  If each pencil was sold at $4 each, Colleen paid $4*20 = $80 more for the 20 extra pencils she has more than Joy.