When we multiply two of the same numbers together, such as $5\boldcdot 5$, we say we are **squaring** the number. We can write it like this: $$5^2$$Because $5\boldcdot 5 = 25$, we write $5^2 = 25$ and we say, “5 squared is 25.”

When we multiply three of the same numbers together, such as $4\boldcdot 4 \boldcdot 4$, we say we are **cubing** the number. We can write it like this: $$4^3$$Because $4\boldcdot 4\boldcdot 4 = 64$, we write $4^3 = 64$ and we say, “4 cubed is 64.”

We also use this notation for square and cubic units.

- A square with side length 5 inches has area 25 in
^{2}.
- A cube with edge length 4 cm has volume 64 cm
^{3}.

To read 25 in^{2}, we say “25 square inches,” just like before.

The area of a square with side length 7 kilometers is $7^2$ km^{2}. The volume of a cube with edge length 2 millimeters is $2^3$ mm^{3}.

In general, the area of a square with side length $s$ is $s^2$, and the volume of a cube with edge length $s$ is $s^3$.