In a 90-minute soccer game, Mark played 20 minutes, then rested after. He then played for another 35 minutes. How long was he on the sideline?
Mark played for a total of 20 + 35 = <T>add(20, 35)=55 minutes.
So, he was on the sideline for 90 - 55 = <T>subtract(90, 55)=35 minutes.
