Indices (powers and bases)
a&sup{n} = a multiplied by itself n times. Year 8 introduces; Year 9 covers index laws.
The base is the number; the index (or power, exponent) is how many times it's multiplied. The three core rules: am×an=am+n, am÷an=am-n, (am)n=amn.
Worked examples
23 × 24 = 27 = 128.
56 ÷ 52 = 54 = 625.
(32)4 = 38.
Frequently asked questions
a<sup>0</sup>?
Anything to the power 0 is 1 (apart from 00, which is debated and avoided in KS3).
Negative indices?
a-n = 1/an. Introduced in Year 9 / GCSE Higher.