Operator overloadin in C#

// C# program to illustrate the
// Binary Operator Overloading 
using System;
namespace BinaryOverload
{
    class Calculator
    {
        public int number = 0;
        // no-argument constructor
        public Calculator() { }

        // parameterized constructor
        public Calculator(int n)
        {
            number = n;
        }
        // Overloading of Binary "+" operator
        public static Calculator operator +(Calculator Calc1,
                                             Calculator Calc2)
        {
            Calculator Calc3 = new Calculator(0);
            Calc3.number = Calc2.number + Calc1.number;
            return Calc3;
        }
        // function to display result
        public void display()
        {
            Console.WriteLine("{0}", number);
        }
    }

    class CalNum
    {
        // Driver Code
        static void Main(string[] args)
        {
            Calculator num1 = new Calculator(200);
            Calculator num2 = new Calculator(40);
            Calculator num3 = new Calculator();

            num3 = num1 + num2;
            num1.display(); // Displays 200
            num2.display(); // Displays 40
            num3.display(); // Displays 240
            Console.ReadKey();
        }
    }
}