conversations.from: human
conversations.value: Mrs. Thompson bought 3 chickens for $3 each. She also bought a bag of potatoes. Mrs. Thompson paid $15 in total. How much did the potatoes cost?
  Can you solve this problem?
conversations.from: assistant
conversations.value: The 3 chickens amount to $3 x 3 = $9.
  Hence, the potatoes cost $15 - $9 = $6.