how is it possible to let 256x256=to 66536 and using distributive does not work like this 250x250=62500 and 6x6=36 and the answers do not ma

256 x 256  =  (250 + 6) x (250 + 6)

So, you must use FOIL:  F = First = 250 x 250,     O = Outside = 250 x 6

               I = Inside = 6 x 250,         L = Last = 6 x 6

You get:  (250 x 250)  +  (250 x 6)  +  (6 x 250)  +  (6 x 6)

     =  62500 + 1500 + 1500 + 36  =  65536

FOIL is an extended distributive property.