Divisibility Rules

1- all numbers
2- even numbers
3- sum of the digits is divisible by 3
4- divisible by 2 twice
5- ends in a 0 or 5
6- divisible by 2 or 3
8- divisible by 2 thrice
9- sum of the digits is divisible by 9
10- ends in 0


Here is a link if you are still having trouble with the divisibility rules:
http://math.about.com/library/bldivide.htm