A rule or fact written with mathematical symbols.

It usually has:

• an equals sign (=)

• two or more variables (x, y, etc)

Example: The formula for the volume of a box is: **V = l × w × h**

Which has these variables:

• V stands for volume,

• l for length.

• w for width,

• h for height,

When l=10, w=5 and h=4, then V = 10 × 5 × 4 = 200

See: Variable