Jeff orders a Halloween costume.  He has to put in a 10% deposit and then pay the rest when he picks it up.  The costume is 40% more expensive than last year's costume, which cost $250.  How much did he pay when picking it up, in dollars?
It cost 250*.4=$<T>multiply(250, 0.4)=100.0 more than his old costume
So it cost 250+100=$<T>add(250, 100)=350
He left a 350*.1=$<T>multiply(350, 0.1)=35.0 deposit
So he had to pay 350-35=$<T>subtract(350, 35)=315
