Sherry:
I'm not sure what the question is. I assume it is to determine the length of each side of the cube with the volume shown.
So for a given Volume of 500 cm^{3}, each side would have a length of the
cube root of 500 cm^{3} or 500^{1/3} cm^{3}.
This can be simplified, through factoring: 500^{1/3} = (2*2*5*5*5)^{1/3} =
(5*4^{1/3}) cm is the length of each side (read as 5 times the cube root of 4)
Similarly, for 800 cm^{3}, each side would have a length of
800^{1/3} = (2*2*2*2*2*5*5)^{1/3} = 2*100^{1/3} cm (read as 2 times the cube root of 100).
Hope this helps!
George T.