using System;

​

public class Program

{

    public static void Main()

    {

        string str = "2.";

        double number;  

        if (double.TryParse(str, out number))

        {

            number = Math.Round(number, 2);

        }

        else

        {

        }

        string formattedNumber = number.ToString("F2");

        Console.WriteLine("number =" + number);

        Console.WriteLine("formatted number =" + formattedNumber);

    }

}