C# - Simple console application in that performs a calculation

Here's an example of a simple console application in C# that performs a calculation:

csharp
using System;

namespace CalculatorApp
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Enter first number:");
            double num1 = Convert.ToDouble(Console.ReadLine());
            Console.WriteLine("Enter second number:");
            double num2 = Convert.ToDouble(Console.ReadLine());
            Console.WriteLine("Enter the operation (+, -, *, /):");
            char operation = Convert.ReadKey().KeyChar;
            Console.WriteLine();

            double result = 0;
            switch (operation)
            {
                case '+':
                    result = num1 + num2;
                    break;
                case '-':
                    result = num1 - num2;
                    break;
                case '*':
                    result = num1 * num2;
                    break;
                case '/':
                    result = num1 / num2;
                    break;
                default:
                    Console.WriteLine("Invalid operation");
                    break;
            }

            Console.WriteLine("Result: " + result);
            Console.ReadKey();
        }
    }
}

In this example, the Program class contains the Main method which is the entry point for the application. The program first prompts the user to enter two numbers and an operation. The operation is then performed using a switch statement and the result is displayed on the console. The Convert.ToDouble method is used to convert the string input from the user into a double type for calculation. The Convert.ReadKey().KeyChar method is used to read the single character operation from the user. Finally, the result is displayed on the console and the program waits for the user to press any key before ending.