Physics-pls help to convert mm to �m?

A physical quantity may be given with a base unit, such as a distance may be given as 30 m. For great or small distances we may introduce a prefix to the unit. For example 3000 m becomes 3 km, or 0.0005 m becomes 0.5 mm. Human red blood cells are about 0.008 mm in diameter. Express this number as a physical quantity using the unit and prefix of '�m'