#2.1A
understand that symbols may be used to represent numbers in equations or variables in expressions and formulae
#2.1B
understand that algebraic expressions follow the generalised rules of arithmetic
#2.1C
use index notation for positive and negative integer powers (including zero)
\(a × a × a = a^3\)
\(a^{-5} = \dfrac{1}{a^5}; \quad a^0 = 1\)
#2.1D
use index laws in simple cases
\(a^m × a^n = a^{m+n}\)
\(a^m ÷ a^n = a^{m-n}\)
\((a^m)^n = a^{mn}\)
#2.1E
use index notation involving fractional, negative and zero powers