Density is simply the total mass of an object divided by the volume that the object occupies. In your example you have an object of mass 30 grams which occupies a volume of 10 cubic centimeters (cm³). So the density μ= mass ÷ volume is (30 g)/(10 cm³) = 3 g/cm³, which is read as "3 grams per cubic centimeter). The Greek letter μ (mu) is commonly used to represent density.