wellll....#s 4,56,7,8,9 just cancel eachother out--thats fluff...so if yer # is 777 u r multiplying it by 20000--so you get 777,oooo(x2)..u then add lets say 4444(ur last 4 digits) twice..but then u divide them by two again so u just get the same # - adding 1 before you multiplied by 250 earliuer...and then sutracting the 250(#8) just cancels out the 250...so tada--u get the same ## 777-4444. Its a pretty good trick.