We can find square root by prime factorization method and also by division method
1 4 1
The simple way to find square roots is as follows:
Suppose take 1225.

Take last two digits as pair.

25 is one pair and 12 is one pair.

unit digit is 5 so the unit digit of its suares also be 5.

write 5 in units place.

Now see next numbers,

12. It is in between 3 and4.

4 is big so take lesser value there you got your answer  35.

Like this also you can find squares roots. 
1 3 1