An aquarium measures 61 cm long, 30.5 cm wide, and 30.5 cm high. If the tank is only filled to 80% capacity with water, how much water is needed for this tank?
11349.05 (and whatever unit of measurement it would be)
The volume is 56745.25, and 80% of that would be 45396.2. In order to find the 20%, or how much water you need, you would subtract 45396.2 from 56745.25 and that leaves you with 11349.05.
