Description: Learn the meaning of cube roots and how to find them. Also learn how to find the cube root of a negative number. We could write the square root of 49, so this is whatever number times itself is equal to 49. If I multiply that number times itself, if I square it, well I'm going to get 49. Now typically and as you advance in math you're going to see that this will change, but typically you say, okay if I'm going to take the square root of something, X has to be non-negative.*Teacher Advisor is 100% free.