Mark has a really bad headache.  He takes 2 Tylenol tablets of 500 mg each and he does every 4 hours for 12 hours.  How many grams of Tylenol does he end up taking?
He takes 12/4=<T>divide(12, 4)=3.0 doses
Each dose is 500*2=<T>multiply(500, 2)=1000 mg
So he takes 3*1000=<T>multiply(3, 1000)=3000 mg
So he takes 3000/1000=<T>divide(3000, 1000)=3.0 grams of Tylenol
