Finding sum of first and last digit using divide and modulo operator in C language

Problem

What is the C program to obtain the sum of the first and last digit of the number, if a four-digit number is input through the keyboard?

Solution

In this program, we are taking a four-digit number at run time and trying to find the sum of first and last digit of that four-digit number by using the logic −

a=n%10;
b=n/1000;
result = a + b;

Let’s apply this logic to find sum of first and last digit of four-digit number −

Example

Following is the C program for finding sum of first and last digit by using divide and modulo operator −

#include<stdio.h>
main(){
   int n,a,b,result;
   printf("Enter a four digit number: ");
   scanf("%d",&n);
   a=n%10;
   b=n/1000;
   result = a + b;
   printf("After adding first and last digit is %d", result);
   getch();
}

Output

When the above program is executed, it produces the following result −

Enter a four digit number: 2345
After adding first and last digit is 7

Program

Following is the C program for a six-digit number and try to find sum of first and last digit −

#include<stdio.h>
main(){
   int n,a,b,result;
   printf("Enter a six digit number: ");
   scanf("%d",&n);
   a=n%10;
   b=n/100000;
   result = a + b;
   printf("After adding first and last digit is %d", result);
   getch();
}

Output

When the above program is executed, it produces the following result −

Enter a six digit number: 346713
After adding first and last digit is 6