C Exercises: Accepts a positive integer less than 500 and prints out the sum of the digits of this number

Last update on September 18 2025 12:35:36 (UTC/GMT +8 hours)

Compute the sum of the digits of an integer less than 500

Write a C program that accepts a positive integer less than 500 and prints out the sum of the digits of this number.

Test data and expected output:
Input a positive number less than 500:
Sum of the digits of 336 is 12

Pictorial Presentation:

Sample Solution:

C Code:

#include <stdio.h>
int main() {
    int a, x = 0, y;

    // Prompt user for input
    printf("Input a positive number less than 500: \n");

    // Read the input value
    scanf("%d", &a);

    y = a;

    if (y < 1 || y > 999) {
        // Display error message if the number is out of range
        printf("The given number is out of range\n");
    } else {
        // Calculate the sum of the digits
        x += y % 10;
        y /= 10;
        x += y % 10;
        y /= 10;
        x += y % 10;

        // Display the result
        printf("Sum of the digits of %d is %d\n", a, x);
    }

    return 0;
}

Sample Output:

Input a positive number less than 500: 
Sum of the digits of 347 is 14

Flowchart:

For more Practice: Solve these Related Problems:

• Write a C program to compute the product of the digits of an integer less than 500.
• Write a C program to calculate the sum of the digits using a recursive approach.
• Write a C program to compute the sum of the digits and check if the result is a prime number.
• Write a C program to sum the digits of a number and then output the reversed sum.

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