Density is calculated as mass divided by volume. If we are given an ice cube of side length 8.00 cm, then the volume of the cube is equivalent to (8.00 cm)^3 = 512 cm^3. Since we have a given mass of 476 g, we can divide:
476 g / 512 cm^3 = 0.930 g/cm^3
So the density of the sample of ice is 0.930 g/cm^3.