Divisibility Rule for 3

If you divide a number by 3 and you get a whole number as an answer (quotient), then that number is divisible by 3.

Instead of simply dividing your number by 3 to see if you get a whole number, you can use what we call the Divisibility Rule for 3.

The Divisibility Rule for 3 is used to determine if a number is divisible by 3. You can also call it the test of divisibility for 3.

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

For example, 213,951 is divisible by 3 because 2 + 1 + 3 + 9 + 5 + 1 = 21 and 21 is divisible by 3.

However, 213,952 is not divisible by 3 because 2 + 1 + 3 + 9 + 5 + 2 = 22 and 22 is not divisible by 3.

Divisibility Rule for 4
Here is the next Divisibility Rule on our list.

Divisibility Rules
Here is a list of all our Divisibility Rules.