Intended for use when base is a large number

x^2 = (x/[exponent])*(x+x), when x is even

x^2 = x * (x+1) - x, when x is odd

576^2= (576/2) *(576+576) = 288 * (1152) = 331776
576^2 = 331776

573^2 = 573 * (573+1) - 573 = 573 * 574 - 573
3238902 - 573
= 328329
573^2 = 328329


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it is taken from:http://library.thinkquest.org/20991/gather/formula/data/136.html