Here is a number written in index form:

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

\(2^4\) is a short way of writing \(2 \times 2 \times 2 \times 2\).

The power or index shows how many times a number has been multiplied by itself.

### Using algebra

\(a^3\) (read as ‘\(a\) cubed’) is a short way of writing \(a \times a \times a\).

\(a\) has been multiplied by itself three times.

Similarly, \(a^2\) (read as '\(a\) squared’) is a short way of writing \(a \times a \).

\(a\) has been multiplied by itself.

\(a^1\) (read as '\(a\) to the power of 1') is written as simply \(a\).