An index, or power, is the small floating number that appears after a number or letter. Indices show how many times a number or letter has been multiplied by itself.
Indices are used to show numbers that have been multiplied by themselves. They can also be used to represent roots, such as the square root, and some fractions. The laws of indices enable expressions involving powers to be manipulated more efficiently than writing them out in full.
Using indices
An index, or power, is the small floating number that appears after a number or letter. The plural of index is indices. Indices show how many times a number or letter has been multiplied by itself.
\(a^2\) (read as '\(a\) squared') means \(a \times a\). \(a\) has been multiplied by itself twice. The index, or power, here is 2.
\(a^3\) (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.