Divisibility Rule of 9: Rule, Examples

Divisibility Rule of 9

A number is divisible by 9 if the sum of its digits is a multiple of 9 (like 9, 18, 27, 36, etc.).

If the sum is divisible by 9, then the whole number is also divisible by 9!

Steps to Check Divisibility by 9

1. Write down the number.

2. Add up all the digits.

3. Check if the sum is a multiple of 9.

4. If yes, the number is divisible by 9.

Examples

Example 1: Is 729 divisible by 9?

1. Number: 729

2. Add the digits: 7 + 2 + 9 = 18

3. 18 is a multiple of 9 (18 ÷ 9 = 2)

729 is divisible by 9.

Example 2: Is 458 divisible by 9?

1. Number: 458

2. Add the digits: 4 + 5 + 8 = 17

3. 17 is not a multiple of 9.

458 is not divisible by 9.

Know the divisibility rule of 11 here.

Try It Yourself:

Are they divisible by 9?
1. 981
2. 1215
3. 354

FAQs

1. What is the divisibility rule of 9 with example?

A number is divisible by 9 if the sum of its digits is divisible by 9. For example, 198 is divisible by 9 because 1 + 9 + 8 = 18, and 18 is divisible by 9. 

2. Is 81 divisible by 9?

The division shows that the number 81 is exactly divisible by 1, 3, 9, 27, and 81.

3. Is 45678 divisible by 9?

To make a number divisible by 9, the sum of its digits must be divisible by 9. In the case of 45678, the sum of its digits is 4 + 5 + 6 + 7 + 8 = 30, which is already divisible by 9. Therefore, no number needs to be subtracted from 45678 to make it divisible by 9.