Definition: The cube root of a number is the value that, when used as a factor three times, gives that number.
What is a cube root?
If c x c x c = n, then c is the cube root of n. Since 6 x 6 x 6 = 216, the cube root of 216 is 6. The symbol is a radical with a small 3.
What are perfect cubes?
1, 8, 27, 64, 125, 216, 343, 512, 729, 1000. These come from cubing 1 through 10.
Can the root be negative?
Yes. The cube root of -64 is -4, because (-4) x (-4) x (-4) = -64. Unlike square roots, cube roots of negatives exist in the real numbers.
How do you use it?
The edge of a cube with volume 343 cubic centimeters is the cube root of 343, which is 7 centimeters. Solve x3 = 1,331 to get x = 11.
How do you estimate?
For the cube root of 100, note that 43 = 64 and 53 = 125, so it falls between 4 and 5, near 4.6.
What is a common mistake?
Dividing by 3. The cube root of 27 is 3, not 9. And the cube of 3 is 27, not 9.