Well if you're referring to rationalizing 
, which simply means, getting rid of the pesky radical at the bottom
well, it boils down to, hmm say... a quantity or even a polynomial, multiplied times 1, is itself, 2*1=2, 3*1 = 3, ducks*1 = ducks, spaghetti * 1 = spaghetti
or whatever * 1 = whatever
and the value of the multiplicand, doesn't change in anyway, is the same thing before and after the multiplication by 1
now....1 can also be a fraction
so.. when you're doing
and the value multiplicand doesn't change in any way
now, try this in your calculator
well, it boils down to, hmm say... a quantity or even a polynomial, multiplied times 1, is itself, 2*1=2, 3*1 = 3, ducks*1 = ducks, spaghetti * 1 = spaghetti
or whatever * 1 = whatever
and the value of the multiplicand, doesn't change in anyway, is the same thing before and after the multiplication by 1
now....1 can also be a fraction
so.. when you're doing
and the value multiplicand doesn't change in any way
now, try this in your calculator