Janna sleeps 7 hours each day during weekdays and 8 hours each day during weekends. How many hours does she sleep in a week?
She sleeps 7*5=<T>multiply(7, 5)=35 hours on weekdays.
She sleeps 8*2=<T>multiply(8, 2)=16 hours on weekends.
35 + 16 = <T>add(35, 16)=51 hours is the amount of time she sleeps in a week.
