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GCSE Maths: Indices & Powers

Practise GCSE Maths indices including the laws of indices, negative powers, fractional powers and zero index. AQA, Edexcel, OCR and Eduqas.

NumberFoundation & HigherAQA · Edexcel · OCR · Eduqas

What you need to know

The concepts examiners test on indices & powers, and what each one is really asking.

Laws of indices
Negative indices
Fractional indices
Zero index
Powers of powers

Where marks get lost

The exam technique that separates a correct method from a correct answer.

  • aᵐ × aⁿ = aᵐ⁺ⁿ (multiply — add powers)
  • aᵐ ÷ aⁿ = aᵐ⁻ⁿ (divide — subtract powers)
  • a^(1/n) = ⁿ√a (fractional index is a root)

Indices & Powers questions students ask

What does a negative index mean?

A negative index means the reciprocal. For example, 2⁻³ = 1/2³ = 1/8.

What does a fractional index mean?

The denominator of a fractional index gives the root. a^(1/2) = √a, a^(1/3) = ∛a. For a^(m/n) = (ⁿ√a)ᵐ.