conversations.from: human
conversations.value: John and Sam were hungry so they ordered an extra-large pizza that was pre-sliced into 12 pieces.  John ate 3 slices while Sam ate twice the amount that John ate.  How many slices of pizza were left?
  Solve it.
conversations.from: assistant
conversations.value: Sam had twice the amount of John so Sam ate 3*2 = 6 slices
  Together, they ate 3+6 = 9 slices
  1 pizza has 12 slices. 9 slices were eaten so 12-9= 3 slices left.