This is not a joke..........its a method to find root Algebraically

SQRT(99) is an irrational, approximately equal to 9.95. [I bet you already knew that it was just a little less than 10]

Here's how I came up with 9.95 without using a calculator:

Since 10^2 = 100,

Therefore,SQRT(99) must be 10-d where d is much smaller than 1.

A little algebra:

  (10-d)*(10-d)=99

  100-20*d+d*d =99

  1-20*d+d*d = 0

  1-20*d     = -d*d,

but d << 1 (much smaller than),so d*d is even less

and for a good approximation, we can assume it's 0:

    1-20*d    ~= 0

    d = 1/20 = 0.05

The actual value of SQRT(99) is 9.94987, so our approximation is pretty good.

Do comment to tell whather I am correct......