conversations.from: human
conversations.value: Can you explain how to solve this math problem: At the patisserie, a single layer cake slice is $4 and a double layer cake slice is $7.  Dusty buys 7 single layer cake slices and 5 double layer cake slices.  If he pays with a $100 bill, how much change does he receive?
conversations.from: assistant
conversations.value: Single layer cake slices cost $4 x 7 = $28.
  Double layer cake slices cost $7 x 5 = $35.
  All the cake slices together cost $28 + $35 = $63.
  He will receive change of $100 - $63 = $37.