not that in order for a number to be divisible by 8 it must first of all be divisible by 2, that is it has to be even.
take a number lets say 1456896
separate the last 3 digits of the number and forget about the rest
now you have 896
divide the last digit by 2 and add it to the new number
896 + (6/2) = 892
now check if this last number (892) is divisible by 4 using the rule i gave on the previous post. look at the last digit, if its 2 or 6 the number will be divisible by 4 if the second to last digit is odd, the last digit is 2 and the second to last is odd and thus 1456896 is divisible by 8.