A school is buying virus protection software to cover 50 devices.  One software package costs $40 and covers up to 5 devices. The other software package costs $60 and covers up to 10 devices.  How much money, in dollars, can the school save by buying the $60 software package instead of the $40 software package?
There are 50/5 = <T>divide(50, 5)=10.0 sets of 5 devices in the school.
So the school will pay a total of $40 x 10 = $<T>multiply(40, 10)=400 for the $40 software package.
There are 50/10 = <T>divide(50, 10)=5.0 sets of 10 devices in the school.
So the school will pay a total of $60 x 5 = $<T>multiply(60, 5)=300 for the $60 software package.
Thus, the school can save $400 - $100 = $<T>subtract(400, 100)=300 from buying the $60 software instead of the $40 software package.
