using System;

​

public class Program

{

    public static void Main()

    {

        double i = 1.0d / 3d;

        Console.WriteLine(String.Format("{0:0.##}", i));

        Console.WriteLine(String.Format("{0:0.############}", i));

        Console.WriteLine("");

        double sum = i + i + i;

        Console.WriteLine(String.Format("{0:0.00}", sum));

        Console.WriteLine(sum);

        Console.WriteLine(Math.Round(sum, 2));

        Console.WriteLine(Math.Round(sum, 2, System.MidpointRounding.AwayFromZero));

​

        Console.WriteLine("");

        sum = i * 3;

        Console.WriteLine(String.Format("{0:0.00}", sum));

        Console.WriteLine(sum);

        Console.WriteLine(Math.Round(sum, 2));

        Console.WriteLine(Math.Round(sum, 2, System.MidpointRounding.AwayFromZero));

        /*double j = 9.37499;

        Console.WriteLine(j);

        Console.WriteLine(String.Format("{0:0.##}", j));

        Console.WriteLine(Math.Round(j, 2, System.MidpointRounding.AwayFromZero));*/

    }

}