Divisibility rules are shortcuts that help you quickly tell if one number can be divided evenly by another, without having to actually do the division.
“Divisible” means the number divides evenly with no remainder.
A number is divisible by 2 if its last digit is even (0, 2, 4, 6, or 8).
Even numbers are always divisible by 2.
A number is divisible by 3 if the sum of its digits is divisible by 3.
If you get a large sum, you can repeat the rule until the sum is small enough.
A number is divisible by 4 if the last two digits form a number divisible by 4.
Only the last two digits matter for this rule.
A number is divisible by 5 if its last digit is 0 or 5.
Numbers ending in 0 or 5 are multiples of 5.
A number is divisible by 6 if it is divisible by both 2 and 3.
You must check both rules: 2 and 3.
A number is divisible by 8 if the last three digits form a number divisible by 8.
For small numbers, you can just check directly. For larger numbers, use the last three digits rule.
A number is divisible by 9 if the sum of its digits is divisible by 9.
This rule is similar to the divisibility rule for 3, but only works when the sum is a multiple of 9.
A number is divisible by 10 if its last digit is 0.
All multiples of 10 end with a 0.