# C Program to Find Sum of Natural Numbers Using While Loop

Problem :- Write A C Program to Find Sum of Natural Numbers Using While Loop

Logic :- What is Natural Number ?
Natural Numbers Are Positive numbers Start With 1 Not 0 ( Zero )
So idea is simple use loop ans initialize with 1 and run into last terms ( Till you Want ) ,you can also print the sum of natural number using formula there are 2 method for solve.
Method 1 :-Using Formula

Natural Number = (N*(N+1))/2

Method 2:- Using Loop

while(count<=n)
{
sum+=count;
++count;
}

Try Yourself C++ Program To Check Number Is Armstrong Or Not

Solution :-

Method 1:-

#include<stdio.h>
int main()
{
int n, count=1, sum=0;

while(1)
{
printf("\nEnter The Natural Number :\n");
scanf("%d",&n);

while(count<=n)
{
sum+=count;
++count;
}

printf("\nSum Of Natural Number Is  = %d\n",sum);

}
return 0;
}

Method 2:-

#include<stdio.h>
int main()
{
int n,sum=0;

while(1)
{
printf("\nEnter The Natural Number :\n");
scanf("%d",&n);

sum=(n*(n+1))/2;
printf("\nSum Of Natural Number Is  = %d\n",sum);

}
return 0;
}

Output:-