7️⃣C Program to Find the Sum of Digits of a Number (With Program and Explanation)

 

🔢 C Program to Find the Sum of Digits of a Number

📌 Problem Statement

Write a C program to find the sum of digits of a given number.

Example

If the input number is 456,
then the sum of digits = 4 + 5 + 6 = 15

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💡 Concept Used

In C, we use:

• % 10 → to extract the last digit of a number

• / 10 → to remove the last digit

We repeat this process using a while loop until the number becomes 0.

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🧠 Algorithm

1. Start

2. Read an integer number

3. Initialize sum = 0

4. While the number is greater than 0

   • Find last digit using num % 10

   • Add digit to sum

   • Remove last digit using num / 10

5. Print the sum

6. End

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💻 C Program: Sum of Digits of a Number

#include <stdio.h>

int main() {
    int num, digit, sum = 0;

    printf("Enter a number: ");
    scanf("%d", &num);

    while (num > 0) {
        digit = num % 10;   // Extract last digit
        sum = sum + digit;  // Add digit to sum
        num = num / 10;     // Remove last digit
    }

    printf("Sum of digits = %d", sum);

    return 0;
}

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▶️ Output Examples

✅ Example 1

Input:

Enter a number: 1234

Output:

Sum of digits = 10
✅ Conclusion
In this program, we learned how to calculate the Sum of Digits of a Number in C.
📘 C Programming Series – What’s Next?
👉 In the next post of this series, we will learn how to Find GCD of Two Numbers with complete explanation and output examples. Stay tuned! 🚀