Olivia and Nigel are traveling in Asia.  Olivia has $112 and Nigel has $139. If together they buy six one day passes to a tourist attraction for $28 per ticket, how much money do they have left?
They have 112+139=$<T>add(112, 139)=251
The passes cost 6*28=$<T>multiply(6, 28)=168
They have 251-168=$<T>subtract(251, 168)=83 left.
