simple calculator

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace csharp_youtube_tutorial
{
    class Program
    {
        static void Main(string[] args)
        {
            //Addition and subtraction calculator. (Simple)
            //This calculator is only limited to addition and subtraction operating<--!-->
            double num1; //We could just do float to save memory but fuck it.
            double num2;

            Console.Write("First number: ");
            num1 = Convert.ToDouble(Console.ReadLine()); /*The method ReadLine() takes the input as a string, so you have to convert it
            into a double.*/
            Console.Write("Second number: ");
            num2 = Convert.ToDouble(Console.ReadLine());

            double addition_sum = num1 + num2;
            double subtraction_sum = num1 - num2;

            Console.WriteLine("Addition: " + addition_sum);
            Console.WriteLine("Subtraction: " + subtraction_sum);

            Console.ReadKey(); //Press a key application ends. //Console[Class] ReadKey()[Function/Method]
        }
    }
}