To study the parity of a number it is enough to check whether or not it is a multiple of the number 2.

Even numbers are the numbers that end with

{0, 2, 4, 6, 8, 10, 12, …, n * 2} = {2n; n is a natural or relative integer}.

Odd numbers are the numbers that end with

1, 3, 5, 7, 9, 11, 13, …, n * 2 + 1 = {2n + 1; n is a natural or relative integer}.

An even number is any number whose remainder of the division over 2 is equal to 0. It is also said that they are multiples of 2.

An odd number is any number whose remainder of the division out of 2 is equal to 1.

Even numbers are divided in two equal parts:

3 + 3 = 6

4 + 4 = 8

7 + 7 = 14

Odd numbers are not shared in two equal parts:

3 = 1 + 2

7 = 3 + 4

41 = 40 + 1

The square of even numbers is an example:

0² = 0

2² = 4

4² = 16

6² = 36

The odd number square is odd, for example:

1² = 1

3² = 9

5² = 25

7² = 49

Note:

Every prime number is an odd number except the number 2.

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#include<stdio.h> #include<stdlib.h> main() { int num; printf("Enter an integer: "); scanf("%d", &num); if(num%2==0) printf("%d is an even number\n",num); else printf("%d is not an even number\n",num); system("pause"); } |