Zoho Second round - adding a digit to all the digits of a number

Adding a digit to all the digits of a number eg digit=4, number = 2875, o/p= 612119

C Program:

#include<stdio.h>
#include<conio.h>
#include<string.h>
int main()
{
    int t,n,i=0;
    char num[100];
    printf("Enter the digit: ");
    scanf("%d",&n);
    printf("Enter the number: ");
    scanf("%s",num);
    printf("o/p ");
    for(i=0;i<strlen(num);i++)
    {
    printf("%d",num[i]-'0'+n);
    }

 getch();
 return 0;
}