A rectangular prism with a volume of 5 cubic units is filled with cubes with side lengths of 1/3 unit. How many 1/3 unit cubes does it take to fill the prism?
A cube with sides each 1/3 unit will have a volume of (1/3)3 = 1/27 cubic units.
If you have a volume of 5 cubic units, then to find the equivalent amount of cubes that each have a volume of 1/27 cubic units,
divide 5 by 1/27 = 5 x 27/1 = 135.