Thread: Help on Sum of Digits Entered

Hey again, I am new to C and trying to wrap my head around it. Just for clarification I am not looking for a full solution, just a shove in the right direction.

In my book in chapter 1 there is an exercise as follows.

If a five digit number is input through the keyboard, write a program to calculate the sum of its digits.

Ok so pretty straight forward. So far in this chapter only variables and operators have been introduced, no decisional statements or loops have technically been learned yet even though I know of them.

I have been playing with the modulus operator to try and solve the problem, but I am not sure how to approach the problem. Some suggestions would be great!

Well the first thing I thought of was taking the number as a string (by using chars). But I'm not sure how to do it without using decision making. I'm not very good at math or algorithms...

What did you try to do with the modulus operator?

The book hinted to use the modulus operator, so I think that the idea behind that is to take the number, and the remainders hint at what the digits were? I don't know if I explained that clearly, not sure how to approach this.

Thanks for the help guys this is what I came up with.

Code:

#include <stdio.h>

int main()
{
    int digits, sum;

    scanf("%d", &digits);

    sum = digits % 10;
    digits /= 10;
    sum += digits % 10;
    digits /= 10;
    sum += digits % 10;
    digits /= 10;
    sum += digits % 10;
    digits /= 10;
    sum += digits % 10;

    printf("%d", sum);
}