Jack has a grove with 4 trees by 5 trees.  It takes 6 minutes to clean each tree.  He gets help to clean the trees so it only takes half as long.  How many hours did he spend cleaning trees?
There were 4*5=<T>multiply(4, 5)=20 trees to clean
So it took 20*6=<T>multiply(20, 6)=120 minutes
That is 120/60=<T>divide(120, 60)=2.0 hours
So he spent 2/2=<T>divide(2, 2)=1.0 hour cleaning
