using System;

public class Program

{

    public static void Main()

    {

        decimal cc = (decimal)0.068627450980392163;

        Console.WriteLine(cc);

        decimal aa = Math.Round(cc, 4); // aa=0.0686

        Console.WriteLine(aa);

        decimal bb = Math.Round(cc, 4) * 100; // bb=6.8599999999999994

        Console.WriteLine(bb == (decimal)6.86);

        Console.WriteLine(bb);

    }

}