John chops down 30 trees.  From each tree, he can make 25 planks.  A table takes 15 planks to make and sells for $300.  He paid $3000 for all the labor.  How much profit did he make?
He got 30*25=<T>multiply(30, 25)=750 planks
So he can make 750/15=<T>divide(750, 15)=50.0 tables
That means he makes 50*300=$<T>multiply(50, 300)=15000
So his profit was 15000-3000=$<T>subtract(15000, 3000)=12000
