C Program to Find Sum of First and Last Digits of a Number

In this C Program, we will find sum of first and last digits of a number. To get the last digit of a number we will use '%' modulus operator. Number%10 will give the last digit of the number. Then we will remove one digit at a time form number using below mentioned algorithm and then store the most significant digit in firstDigit variable.

Sum of first and last digits of 2534 = 2 + 4 = 6

Required Knowledge

Algorithm to find first and last digits of a number
  • Get least significant digit of number (number%10) and store it in lastDigit variable.
  • Remove least significant digit form number (number = number/10).
  • Repeat above two steps, till number is greater than 10.
  • The remaining number is the first digit of number.

C program to find sum of first and last digits of a number

#include <stdio.h>

int main() {  
    int num, temp, firstDigit, lastDigit, sum;  
   
    printf("Enter a Number\n"); 
    scanf("%d", &num);  
    temp = num;
    
    /* get last digit of num */
    lastDigit = num %10;
    
    while(num > 10){
        num = num/10;
    } 
    firstDigit = num;
    sum = firstDigit + lastDigit;
    printf("Sum of first and last digit = %d",temp,sum);  
  
    return 0;  
}
Output
Enter a Number
2436
Sum of first and last digit = 8
Enter a Number
2222
Sum of first and last digit = 4

Related Topics
C program to print digit of a number in words
C program to add digits of a number
C program to count number of digits in an integer
C program to find sum of digits of a number using recursion
C program to reverse a number using recursion
C program to convert decimal number to octal number
C program to find perfect numbers between 1 to N using for loop
C program to print all factors of a number using for loop
C program to print all prime factors of a number
List of all C programs