How to Calculate Cube Roots in Your Head
Cube root is a number that must be multiplied times itself three times to equal a given number. Do you know the cube root of 39304? You can learn how to solve this and other cube roots very quickly using the steps below.
Step 1: Memorize the cubes of each number from 1 to 10, especially the last digit. See the video below for a chart.
Step 2: Look at the last digit of your number and write down the corresponding number. 4 in the case of 39304.
Step 3: Now ignore the last three digits: 3 0 4.
Step 4: Find the closest cube without going over. 39 is closest to cube of 3. That gives us the other part: 3.
Step 5: Put the numbers together to get 34.
34 is the cube root of 39304.
34 * 34 * 34 = 39304.
https://youtu.be/Ds8ijPsg26g
Source: http://www.engineering-society.com/2018/02/how-to-calculate-cube-roots-in-your-head.html