The spec for this section includes:
Fundamental (base) units.
Use of mass, length, time, amount of substance, temperature, electric current and their associated SI units.
SI units derived.
Knowledge and use of the SI prefixes, values and standard form.
The fundamental unit of light intensity, the candela, is excluded.
Students are not expected to recall definitions of the fundamental quantities.
Content
Dimensional analysis is not required. Students should be able to use the prefixes:
T, G, M, k, c, m, μ, n, p, f,
Students should be able to convert between different units of
the same quantity, eg J and  , J and  .
Can someone just explain SI units in simpleton terms.