Length, time and volume are all examples of quantities that can be measured.
A unit of measurement is one unit of a quantity, for example, one second.
Standard units of measurement are the units most typically used to measure a quantity.
Kilometres (km) and miles are the standard units used to measure long distances.
Smaller lengths are measured in metres (m), centimetres (cm) or millimetres (mm).
The distance from London to Manchester is approximately 264 km or 164 miles.
The battery in the picture is 2.6 cm or 26 mm wide.