If a number ends with 5 and you want to find its square root, this trick might be worth looking into.
So, for example, we have 105.
Take the 5 in the units place and square it. 5^2 = 25.
Now, take the 10. The succeeding number is 11. Do 10x11 = 110.
Concatenate both the numbers (110 and 25), and you get the resulting square of 105, i.e 11025.
My grandpa taught me this trick today, and I thought it might be a fun trick to learn. Hope it helps!
