Using an index or power

Explore updated revision resources for GCSE Maths: How to use an index or power, with step-by-step slideshows, quizzes, practice exam questions, and more!

An index, or a power, is the small floating number that goes next to a number or letter. The plural of index is indices.

Indices show how many times a number or letter has been multiplied by itself.

Here is a number written in index form:

2 is the base number and 4 is the index or power.

2⁴ is a short way of writing \(2 \times 2 \times 2 \times 2\).

\(a^2\) (read as '\(a\) squared’) means \(a \times a\). \(a\) has been multiplied by itself.

a^3 (read as ‘a cubed’) means a \times a \times a. a has been multiplied by itself three times.

\(a^4\) (read as ‘\(a\) to the power of 4’) means \(a \times a \times a \times a\). \(a\) has been multiplied by itself four times, and so on.

Welcome to My Bitesize, let's get you set up!