HOW TO FIND THE CUBE ROOT OF A NUMBER EASILY

FINDING THE CUBE ROOT EASILY

To find the cube root of any number with this trick, you only need to remember the cubes of the numbers from 1 to 10. Let us learn this trick with the help of the number ‘15625’.

CUBES OF THE NUMBERS FROM 1 TO 10

1³ = 1

2³ = 8

3³ = 27

4³ = 64

5³ = 125

6³ = 216

7³ = 343

8³ = 512

9³ = 729

10³ = 1000

CUBE ROOT OF 15625

So, we can learn this trick with the help of the number ‘15625’. We need to follow some steps to get the root of this number.

STEP 1 – Look at the unit digit of 15625, which is 5.

STEP 2 –  Now, we need to see the cubes of numbers ‘1 to 10’ and see the cube of which number has ‘5’ in its units place. We can see that the cube of ‘5’ is ‘125’ and it has 5 in its unit place.

This helps in getting the unit digit of the cube root of 15625, which is 5.

STEP 3 – Look at the number 15625, ignoring the last three digits of the number from the unit place, we are left with 15.

STEP 4 – Now, We have to find two numbers between the cubes of which 15 lies. As per the list above, 15 lies between 8 and 27. They are cubes of 2 and 3 respectively. So, the required numbers, in this case, are 2 and 3.

STEP 5 – We have to choose between 2 and 3 which will be placed in the tenth place of the cube root of 15625, so we will always choose the smaller number which is ‘2’ in this case.

Hence, we get the cube root of 15625, which is 25. In this way, we can find many other cube roots without using the longer methods.

We can find the cube root of a ‘4-digit number to a 6-digit number’ easily from this process.

But, for a 7-digit number, we need to remember the cubes of the number from 11 to 20 because the cube root of a 7-digit number is a 3-digit number. Then, we can follow all the steps mentioned above. For ‘STEP 5’ above, we need to find the two-digit number from 11 to 20, which will be placed in the tenth and hundredth place.