static void Main(string[] args)
{
var calc4 = new Calculator4();
calc4.GetNumber("First"); calc4.GetNumber("Second");
calc4.AddNumbers();
PrintResult(calc4);
Console.ReadKey();
}
static void PrintResult(Calculator4 calc)
{
//Console.WriteLine($"Your result is {result}.");
Console.WriteLine(String.Format("Your result is {0}.", calc.Result));
}