Need help with creating Binary Class

[rrrct31]

I am trying to create a class to manipulate binary number including +, -, & * functions. here is what i already have.

#include <iomanip.h>
#include <stdio.h>
#include <iostream.h>
#include <stdlib.h>

class bin_num{
   char data[8];
   int todec(bin_num x);
   bin_num tobin(int x);
   bin_num operator +(bum_num x);
   bin_num operator -(bum_num x);
   bin_num operator *(bum_num x);}

bin_num::int todec(bin_num x){
   int y;
   y = strtol(x, NULL, 2);
   return y;
}

bin_num::bin_num tobin(int x){
   char bnum[8];
   itoa(x, bnum, 2); 
   return bnum;
}

bin_num::bin_num operator +(bum_num x){
}

bin_num::bin_num operator -(bum_num x){
}

bin_num::bin_num operator *(bum_num x){
}

i don't quite know what the operator functions should be. If anyone could help, PLEASE!!!!