question: While on vacation in Bali, Thea bought a hat from a craftsman worth $70. If she gave the craftsman four $20 bills, how much change did she get?
answer: If she gave the craftsman four $20 bills, the total amount of money she gave to the craftsman is 4*$20 = $<<4*20=80>>80.
  Since the hat was worth $70, the craftsman gave her change equal to $80-$70=$10
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