public static void Main() { Console.WriteLine("Select an option: "); Console.WriteLine(" 1 C to F"); Console.WriteLine(" 2 F to C"); Console.WriteLine(" 3 Miles to Km"); Console.WriteLine(" 4 Km to Miles"); Console.Write("=>"); string input = Console.ReadLine(); int opt = Int32.Parse(input); Console.Write("Value to convert: "); input = Console.ReadLine(); double value = Double.Parse(input); double result; switch (opt) { case 1: result = TempConverter.CelsiusToFahr(value); break; case 2: result = TempConverter.FahrToCelsius(value); break; case 3: result = DistanceConverter.MileToKm(value); break; case 4: result = DistanceConverter.KmToMile(value); break; default: Console.WriteLine("Invalid option"); return; } Console.WriteLine("Result: {0}", Math.Round(result, 2)); }