## Thursday, May 8, 2014

### Divisibility - 3

Category: Arithmetic

"Published in Newark, California, USA"

Divisibility by 3:

How do you know that a number is divisible by 3? Well, a number is divisible by 3 if the sum of the digits are divisible by 3 or multiples of 3. You need to remember or memorize the multiplication table for this one.

Example 1:

The first thing that we need to do is to inspect the given number if it is divisible by 3 or not. Let's add the digits as follows

You can add the digits again as follows

Since 4 is not a multiple of 3, then the given number is not divisible by 3. There's a remainder of 1 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 3 or not. Let's add the digits as follows

You can add the digits again as follows

Since 9 is a multiple of 3, then the given number is divisible by 3. 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 3. Again, there should be no remainder or a fraction in the division.