C Program to Find Sum of First and Last Digit of a Given Number

Introduction

In this tutorial, we will write a C program to find the sum of the first and last digit of a given number. This is a simple yet effective way to practice working with digits in C programming. The task involves extracting the first and last digits from an integer and calculating their sum.

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Steps to Find the Sum of First and Last Digit

1. Extracting the Last Digit
   The last digit of a number can be obtained using the modulus operator (% 10). For example, the last digit of 1234 is 4, which can be found using 1234 % 10.
2. Extracting the First Digit
   To extract the first digit, we divide the number by 10 repeatedly until the number becomes a single-digit number. For instance, for 1234, dividing repeatedly gives 1.

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C Program to Find Sum of First and Last Digit

#include <stdio.h>

int main() {
    int num, firstDigit, lastDigit, sum;

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

    // Finding the last digit
    lastDigit = num % 10;

    // Finding the first digit
    firstDigit = num;
    while (firstDigit >= 10) {
        firstDigit = firstDigit / 10;
    }

    // Calculating the sum
    sum = firstDigit + lastDigit;

    // Displaying the result
    printf("Sum of first and last digit is: %d\n", sum);

    return 0;
}

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Explanation of the C Program

• Input: The program takes an integer as input from the user.
• Last Digit: We calculate the last digit by using the modulus operator.
• First Digit: We divide the number by 10 until it becomes a single-digit number.
• Sum Calculation: Finally, we add the first and last digits and display the result.

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Sample Output

Enter a number: 54321
Sum of first and last digit is: 6

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Use Cases and Applications

This program is useful in:

• Basic arithmetic problems
• Number manipulation
• Understanding how to work with digits in C

It helps you practice working with loops, arithmetic operations, and input handling.

Conclusion

By writing this C program to find the sum of the first and last digit, you can practice extracting specific digits from a number. This is a basic but essential skill in programming, especially when working with numerical data and user input.