Density is an example of a compound measure, which is one that involves more than one unit of measurement.

Density is a measure of mass (e.g. kg, g) in relation to unit volume (e.g. m^{3}, cm^{3}) and can be measured in kg/m^{3}, g/cm^{3} etc.

We calculate densities using the following formula:

Density = Mass ÷ Volume

**Example**

A large block of oak has a mass of 185 kg and a volume of 0.25 m^{3}. Find its density in kg/m^{3}.

**Answer**

**Density** = Mass ÷ Volume = 185 ÷ 0.25 = **740 ** kg/m^{3}.