6th grade math
posted by Karen .
If the volume of a rectangular solid is 80 cu inches, what dimensions will give the least amount of surface area?

a square will give the least surface area.
s^3=80
side length= cuberoot 80 
not a cube, as they have not done cube roots yet. I know the answer, which would be 4x4x5, but looking for a pattern or easy way to explain it.