We use many different units of measurement and they tell us what it is that we are measuring. Here are some of the common units of measurement that are used.
Length: mm, cm, m and km
Area: mm2, cm2, m2 and km2
Volume: mm3, cm3, m3 and km3
Capacity: mL, L, kL, ML
Mass: mg, g, kg, tonne
Sometimes we need to determine what is the most appropriate unit for measuring a particular item so that we do not end up with unreasonably large or small numbers.
Have a look at this video to learn how to choose the most appropriate units of measurement.
Choose the most appropriate unit of measure for the mass of a biscuit.
It is most appropriate to use centimetres to measure:
a running track
It is most appropriate to use cubic metres ($m^3$m3) to measure:
a swimming pool
a salad bowl