1)Starting from the right-hand side, put a slash after every second digit as you go to the left.

2)We have n slashes and the group on the left-hand side is only one digit, x, so we need to pick the largest single digit, which when squared, the square is less than or equal to x.

3)We square the first digit of the answer and subtract it from the first group in the number.

4)The result of the subtraction in step 3 was 2. We use this to find the second digit of our answer. We halve the 2 then multiply by ten.

5) square the right-hand digit.Multiply the two digits of the answer then double the result. We add the carry now.

6)We subtract the left-hand digit of our calculation under the answer from the result of the subtraction in step 3.

7)We now subtract the middle digit from our calculation under the answer from under the dividend.

8)We keep repeating the above steps till we reach the final slash.and that will be our answer.

For a better visual representation with example you can search for how to calculate 12 digit number square root on youtube as well as on google itself.

Hope this helps.