Switch Case

#include <iostream.h>
void main()
{
  float a,b,i;
  cout<< "This is a simple no GUI calculator which can Add, Subtract, Multiply, Divide.\n";
  cout<< "Enter '1' to add, '2' to Subtact, '3' to Multiply, '4' to Divide.\n";
  cin>> i;
  cout<< endl;
  switch(i)
    {
     case 1:
     cout<< "Your option was Addition.\n";

     cout<< "Enter the First number...\n";
     cin>> a;
     cout<< endl;
     cout<< "Enter the Second number...\n";
     cin>> b;
     cout<< endl;
     cout<< "Sum of the numbers is "<<a+b;
     cout<< endl;
     break;
    case 2:
     cout<< "Your option was Subraction. Format is 'First number-Second number'.\n";

     cout<< "Enter the First number...\n";
     cin>> a;
     cout<< endl;
     cout<< "Enter the Second number...\n";
     cin>> b;
     cout<< endl;
     cout<< "Difference of the numbers is "<<a-b<<".\n";
     break;
    case 3:
     cout<< "Your option was Multiplication. The Multiplication is only of two numbers.\n";

     cout<< "Enter the First number...\n";
     cin>> a;
     cout<< endl;
     cout<< "Enter the Second number\n...";
     cin>> b;
     cout<< endl;
     cout<< "Product of the numbers is "<<a*b<<".\n";
     break;
    case 4:
     cout<< "Your option was Division. The first number is divided by the second number.\n";

     cout<< "Enter the First number...\n";
     cin>> a;
     cout<< endl;
     cout<< "Enter the Second number...\n";
     cin>> b;
     cout<< endl;
     cout<< "Difference of the numbers is "<<a/b<<".";
     break;
    default:
    cout<< "The program does not understand your input. Try one of the the supported ones.\n";
    break;
  }
 cout<< "Thank you for trying this program";
}