How Do You Find the Cube of a Number?

In order to find the cube of a number, multiply the number by itself three times. A cube is expressed in exponential form as B^3, which is read as B cubed or B raised to the third power. In this exponent, B is known as the base and 3 is the power.

The cube B^3 can be expressed in expanded form as B x B x B. To evaluate any cube, it is simply a matter of performing the multiplication indicated. For example, 8 cubed or 8^3 is 8 x 8 x 8, which equals 512. The cube of a whole number is defined as a perfect cube.

While learning about cubes, students also are exposed to the opposite of a cubed number, which is the cube root. To express a cube root of a number, a radical sign is used along with the number 3 outside the radical sign, which is called the index. The cube root of a number C can also be given as C ^ 1/3. To find the cube root of 512, this can be expressed as 512 ^ 1/3, which is 8. It is also possible to find the cube roots of negative numbers. For example, (-512) ^1/3 or the cube root of -512 is equal to -8.