C++ menu based program for XI standard

Here is the menu based program on C++ language. I have defined four functions in the class. From 'void main ()' function two numbers and the operator are entered by user and according to the entered operator, function is invoked.

 #include< iostream.h>

#include< conio.h>

class menu

{

 public:

 void add(int a, int b)

 {

  cout<<"\nSum="<<(a+b);

  }

   void sub(int a, int b)

 {

  cout<<"\nResult="<<(a-b);

  }

   void multiplication(int a, int b)

 {

  cout<<"\nResult="<<(a*b);

  }

   void div(int a, int b)

 {

  cout<<"\nResult="<<(a/b);

  }

  } ;

void main()

{

clrscr();

 int a,b;

 char ch;

 menu ob;

 cout<<"\nEnter two numbers:";

 cin>>a>>b;

 cout<<"\nEnter operator(+,-,*,/):";

 cin>>ch;

 switch(ch)

 {

   case '+':

                ob.add(a,b);

                break;

     case '-':

                ob.sub(a,b);

                break;

    case '*':

                ob.multiplication(a,b);

                break;

    case '/':

                ob.div(a,b);

                break;

     default:

     cout<<"\nWrong operator";

     break;

     }

     getch();

     }