A square root of a number is a value that, when multiplied by itself, gives the number.

Example: 4 × 4 = 16, so a square root of 16 is 4.

Note that (−4) × (−4) = 16 too, so −4 is also a square root of 16.

The symbol is **√** which always means the positive square root.

Example: √36 = 6 (because 6 x 6 = 36)

Play with it here:

../numbers/images/square-root.js

See: Cube Root