Sum of digits of a number down to a single digit.

PROCEDURE:-

      1.enter integer value n
      2.repeat  step 3 to 8 until n is greater than 9
      3.set sum to 0
      4.repeat  step 5 to 7 until n is greater than
      5. find the modulo 10 for n and store result in r
      6.add r to previous sum
      7. find new value of n by dividing it by 10
      8 set  n to sum
      9. print sum


CODE:-

#include<stdio.h>
void main()
{
  int n,m,sum,r;
  printf(“enter value for n”);
  scanf(“%d”,&n);
  m=n;
  while(n>9)
  {
    sum=0;
    while(n>0)
     {
       r=n%10;
       sum=sum+r;
       n=n/10;
     }
   n=sum;
}
printf(“sum of %d down to single digit is %d”,m,sum);
}


Input:- enter value for n 137
Output:- sum of 137 down to single digit is 2