Quick trick to find the cube root of a number
To find the cube root of a number, you want to find some number that when multiplied by itself twice gives you the original number. Finding the cube root can be a time-consuming task.
However, there are ways to quickly, easily and accurately calculate the cube root of a given number.
Let’s learn how to find the cube root of a number in less than 5 seconds.
For finding the cube of any number, we have to memorise the values in the table
Example 1
We have a number 39304, let’s learn 4 steps to find the cube root of 39304.
- Check the unit digit of the number, here it is 4 (39304)
- Look for 4 in the last digit column of the table, the number corresponding to 4 is 4, so the unit digit of our answer is 4.
- Since we have to find the cube root, remove the last three 3 digits, i.e. 304, hence we are left with 39.
- Look for the number in the cubes column just less than 39, we have 27. The corresponding number for 27 is 3.
Therefore, our answer is 34
Let us solve another example to show how the answer can be achieved in less than 5 seconds.
Example 2
We have to calculate the cube root of 474552
- Look at the unit digit of 474552, here it is 2.
- The corresponding number for 2 in the last digit column is 8, so the unit digit of our answer is 8.
- Remove the last 3 digits i.e. 552. Hence, we are left with 474.
- Find out the number just less than the number 474 in the cubes column of the table. It is 345 and the corresponding number for this is 7.
Therefore, our answer is 78.
Example 3
We have to calculate the cube root of 17576
- Find the unit digit, here it is 6.
- Find out 6 in the last digit column of a table and the corresponding number for 6 is 6. So, the unit digit of our answer is 6.
- Remove the last 3 digits of the number i.e. 576. Hence, we are left with 17.
- Find out the number just less than the number 17 in the cubes column of the table. It is 8 and the corresponding number in the numbers column for 8 is 2.
Therefore, our answer is 26.
Example 4
Let say, we have to calculate the cube root of 59319.
- Check the unit digit of the number, i.e. 9.
- Find out 9 in the last digit column of the table and the corresponding number for 9 in the number column is 9. So, the unit digit of our answer is 9.
- Remove the last 3 digits of the number, i.e. 319. Hence, we are left with 59.
- The number smaller than 59 in the cubes column is 27 and the corresponding number to that is 3.
Therefore, our answer is 39
Watch more such tips and tricks to solve Mathematics questions within seconds, click https://www.youtube.com/watch?v=cm_T8r0D5Fw&t=44s