for squaring you don't have to take any base.
You can do it like this:
for eg:
sq. of 32 :
We'll take the nearest ten
So, nearest 10 of 32 is 30
Now, 32 is two more than 30
so, we'll multiply 30 x (32+2)i.e, 30 x 34 = 1020
now we'll add sq. of 2 in the resulting product as above
i.e, 1020 + 4 = 1024
Therefore, sq. of 32 is 1024