Unit is expressed as singular. Eg : This ladder is 10 metre long.

Unit having a person's name is expressed in lowercase. Eg : The force acting on the piston is 10 newton.

Length

1 km = 10 hm
1 km = 1000 m
1 hm = 100 m
1 m = 10 dm
1 dm = 10 cm
1 cm = 10 mm

Area

1 km2 = 100 hectares
1 hectare = 100 ares
1 are = 100 m2
1 m2 = 100 dm2
1 dm2 = 100 cm2
1 cm2 = 100 mm2

Volume

1 m3 = 1000 litre
1 litre = 1 dm3
1 litre = 1000 cc
1 litre = 1000 ml

Mass (Weight)

1 tonne = 1000 kg
1 kg = 1000 g
1 g = 1000 mg

Time

Unit : second (s)