Divisibility Rules

Rule #1: divisibility by 2

A number is divisible by 2 if it's last digit is 0,2,4,6,or 8.

For instance, 8596742 is divisible by 2 because the las t digit is 2.

Rule # 2: divisibility by 3:

A number is divisible by 3 if the sum of its digits is divisible by 3

For instance, 3141 is divisible by 3 because 3+1+4+1 = 9 and 9 is divisible by 3.

Rule # 3: divisibility by 4

A number is divisible by 4 if the number represented by its last two digits is divisible by 4.

For instance, 8920 is divisible by 4 because 20 is divisible by 4.

Rule #4: divisibility by 5

A number is divisible by 5 if its last digit is 0 ot 5.

For instance, 9564655 is divisible by 5 because the last digit is 5.

Rule # 5: divisibility by 6

A number is divisible by 6 if it is divisible by 2 and 3. Be careful! it is not one or the other. The number must be divisible by both 2 and 3 before you can conclude that it is divisible by 6.



Rule #8: divisibility by 9

A number is divisible by 9 if the sum of its digits is divisible by 9.

For instance, 3141 is divisible by 9 because the sum of its digits is divisible by 9.

Rule # 9: divisibility by 10

A number is divisible by 10 if its last digits is 0

For instance, 522480 is divisible by 10 because the last digit is 0.