An auto shop has a part that Clark needs for $80. Clark buys 7 of them and got a discount. If Clark only had to pay $439, how much was the discount?
Originally the car parts would be a total of 80*7 = <T>multiply(80, 7)=560 dollars.
Clark got a discount for 560-439 = <T>subtract(560, 439)=121 dollars.
