Sum of Digits in a 5-Digit Number in C

Summary: This C program reads a five-digit number and calculates the sum of its individual digits using arithmetic operations. It demonstrates digit extraction using modulo and integer division.

#include <stdio.h>
#include <string.h>
#include <math.h>
#include <stdlib.h>

int main() {
    int n;
    scanf("%d", &n);

    int sum = 0;
    // Extract each digit and add to sum
    sum += n % 10;     // last digit
    n = n / 10;

    sum += n % 10;     // 4th digit
    n = n / 10;

    sum += n % 10;     // 3rd digit
    n = n / 10;

    sum += n % 10;     // 2nd digit
    n = n / 10;

    sum += n % 10;     // 1st digit

    printf("%d", sum);
    return 0;
}

Explanation:

Reading Input:
The program uses scanf() to read a 5-digit integer from the user.

Digit Extraction:
Each digit is extracted using the modulo operator %, which returns the last digit. The number is then reduced using integer division by 10.

Step-by-Step Breakdown:

• n % 10: extracts the last digit
• n / 10: removes the last digit
• This process is repeated five times

Summation Logic:
Each extracted digit is added to a running total stored in the sum variable.

Assumptions:
This program assumes the input is a five-digit number. No input validation is included.