## Divisibility by 4

This is the second post in the **Divisibility Rules Series**. In the last post, we discussed about divisibility by 2. In this post, we discuss divisibility by 4.

Now, how do we know if a number is divisible by ?

Four divides because . It is also clear that four divides and all multiples of . Therefore, four divides multiples of , , and . **In general, divides , where is an integer greater than .**

Now, how do we know if a number that is not a power of is divisible by . Let us try a few examples.

**Example 1:** Is divisible by ? is equal to and is divisible by . Since is also divisible by , therefore, id divisible by .

**Example 2:** Is divisible by ? is equal to . Now, is divisible by . Since is not divisible by , therefore, is not divisible by .

**Example 3:** Is divisible by ? . Now, is divisible by (it’s a multiple of 100), and is not divisible by . Therefore, is not divisible by .

By now, you would have realized that we just test the last 2 digits of the numbers if we want to find out if it is divisible by 4: 1**48**, 3**62**, and 34**26**. » Read more