How do you know if a number is divisible by 3

You can easily tell if a number is divisible by 3 by performing the divisibility test of 3 on the number.

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

Let us see a few examples.

Explanation:

Are 57438 and 2369 divisible by 3?

The sum of digits of 57438 = 5+7+4+3+8 = 27

27 is divisible by 3 and thus, 57438 is divisible by 3.

The sum of digits of 2369 = 2+3+6+9 = 20

20 is not divisible by 3 and thus, 2369 is not divisible by 3.

Hence, a number is divisible by 3 if the sum of its digits is divisible by 3.