## Thursday, May 15, 2014

### Divisibility - 9

Category: Arithmetic

"Published in Newark, California, USA"

Divisibility by 9:

How do you know that a number is divisible by 9? Well, a number is divisible by 9 if the sum of the digits is a multiple of 9, then the given number is divisible by 9. You can repeat the process until the result is a multiple of 9.

Example 1:

The first thing that we need to do is to inspect the given number if it is divisible by 9 or not. Let's add the digits as follows

Since 8 is not a multiple of 9, then the given number is not divisible by 9. There's a remainder of 8 in the division. The answer or a quotient must be a whole number itself. You should not have a fraction or a remainder in the final answer.

Example 2:

The first thing that we need to do is to inspect the given number if it is divisible by 9 or not. Let's add the digits as follows

Since 9 is a multiple of 9, then the given number is divisible by 9. There's no remainder or a fraction in the division.

You should consider in studying the divisibility of a number because you will use these principles later when you will study higher Math subjects that involves the division of a number, simplifying fractions, and even factoring.

This method can also be used for negative integers as long as the sum of the digits is a multiple of 9. Again, there should be no remainder or a fraction in the division.