# C Program to Find the Sum of First N Natural Numbers ## Find the Sum of first N Natural Numbers

In this article we will see C Program to Find the Sum of First N Natural Numbers. A Natural number is a same as Counting number. They are used to Count the numbers of real physical object. Natural number start from 1 and go on infinite. The positive numbers 1, 2, 3… are known as natural numbers.

Example:
Natural number={1,2,,4,5,6,…….}.
Formula for Sum of First  N natural numbers is : n(n+1)/2.
If you want to add first 5 Natural number then we find the Sum of 1+2+3+4+5 =15.

## Algorithm

• Step 1. Start
• Step 2. Enter a number (N).
• Step 3. Use formula to calculate the sum of N natural number || Sum=(n*(n+1))/2.
• Step 4. Print sum of N Natural Number.
• Step 5. Stop ## C code

```#include<stdio.h>
int main()
{
int sum=0,n;
printf("Enter the first N Natural Number\n“);
scanf("%d",&n);
sum=(n*(n+1))/2;
printf("sum is %d",sum);
return 0;
}```

### Output

```Enter the first N Natural Number : 7
Sum is 28
``` 