Natural number

Natural numbers are numbers that are common and clear in nature. As such, it is a whole, non-negative number.

Logic

To print the sum of first N natural numbers, we need to run one loop from 1 to N, and each time inside the loop we have to add / sum value of “i” (current number) into one temporary variable.

Once the loop is over, outside of the loop we have to print a temporary variable containing the sum of natural numbers.

See also: Print first N natural numbers using for loop

Program

SumOfNatural.CCopy
#include <stdio.h>

int main() {

    int i, num, sum = 0;

    // Take number from user
    printf("Enter any number : ");
    scanf("%d", &num);

    for(i = 1; i <= num; i++) {

        sum += i;
    }

    printf("\nSum of first %d natural numbers = %d", num, sum);

    return 0;
}
Try It

Output

Enter any number : 50
Sum of first 50 natural numbers = 1275