John's hair grows 1.5 inches every month.  Every time it gets to 9 inches long he cuts it down to 6 inches.  A haircut costs $45 and he gives a 20% tip.  How much does he spend on haircuts a year?
He cuts off 9-6=<T>subtract(9, 6)=3 inches when he gets a haircut
That means he needs to cut it every 3/1.5=<T>divide(3, 1.5)=2.0 months
So he gets 12/2=<T>divide(12, 2)=6.0 haircuts a year
He gives a 45*.2=$<T>multiply(45, 0.2)=9.0 tip
So that means each hair cut cost 45+9=$<T>add(45, 9)=54
So he pays 54*6=$<T>multiply(54, 6)=324 a year
