sum of individual digits in c using function

1//program to find the sum of digits:
2
3#include<stdio.h>
4int main()
5{
6  int num,sum=0,r,temp;
7  printf("Enter the number:\n ");  //taking input from the user
8  scanf("%d",&num);
9  
10  temp=num;           //assigning num to temporary variable
11  
12  while(temp!=0)
13  {
14    r=temp%10;
15    sum=sum+r;
16    temp=temp/10;
17  }
18  printf("\nGiven number = %d",num);
19  printf("\nSum of the digits = %d",sum);
20}
21
22//code By dungriyal

1#include <stdio.h>
2int main()
3{
4   int n, sum = 0, r;
5
6   printf("Enter a number\n");
7
8   for (scanf("%d", &n); n != 0; n = n/10) {
9      r = n % 10;
10      sum = sum + r;
11   }
12
13   printf("Sum of digits of a number = %d\n", sum);
14
15   return 0;
16}

1#include <stdio.h>
2
3int individualSum(num);
4
5void main ()
6{
7    int num, ret;
8
9    ret = individualSum(num);
10    printf("\nThe sum of individual digit is %d\n", ret);
11}
12
13int individualSum(num)
14{
15    int i, rem, sum = 0;
16    printf("Enter the number: ");
17    scanf("%d",&num);
18
19    while(num!=0)
20    {
21        rem = num % 10;
22        num = num /10;
23        sum = sum + rem;
24    }
25  	
26  return sum;
27}
28

1Enter the number
2300
3Given number = 300
4Sum of the digits 300 = 3
5 
6 
7Enter the number
816789
9Given number = 16789
10Sum of the digits 16789 = 31