Console.ForegroundColor
                    = ConsoleColor.Blue;

            Console.WriteLine("Enter a number: ");
            double num1 = Convert.ToDouble(Console.ReadLine());

            Console.Write("Enter an Operator: ");
            string operation = Console.ReadLine();

            Console.WriteLine("Enter a number: ");
            double num2 = Convert.ToDouble(Console.ReadLine());

            switch (operation) {
                case "+":
                    Console.WriteLine(num1 + num2);
                    break;
                case "-":
                    Console.WriteLine(num1 - num2);
                    break;
                case "*":
                    Console.WriteLine(num1 * num2);
                    break;
                case "/":
                    Console.WriteLine(num1 / num2);
                    break;
            }