Dirk sells amulets at a Ren Faire.  He sells for 2 days and each day he sells 25 amulets.  Each amulet sells for 40 dollars and they cost him 30 dollars to make.  If he has to give 10% of his revenue to the faire, how much profit did he make?
He sold 2*25=<T>multiply(2, 25)=50 amulets
So he made 40*50=$<T>multiply(40, 50)=2000
The faire took 2000*.1=$<T>multiply(2000, 0.1)=200.0
So he kept 2000-200=$<T>subtract(2000, 200)=1800
The amulets cost 50*30=$<T>multiply(50, 30)=1500 to make
So he had a profit of 1800-1500=$<T>subtract(1800, 1500)=300
