using System;

public class Program

{

    public static void Main(string[]args)

    {

        int number1;

        int number2;

        int sum; 

        int product;

        int difference;

        string firstName;

        Console.WriteLine("Hello, what is your name. ");

        firstName = Console.ReadLine();

        Console.WriteLine( firstName + " Please input a number between 1 and 9 ");

        number1 = int.Parse(Console.ReadLine());

        if( number1 > 9 )

        { number1 = 5; }

        else if( number1 < 0)

        { number1 = 5; }

        //else

        //{ Console.WriteLine("Great job, your number is " + number); }

        Console.WriteLine(firstName + " Please input another number between 1 and 9 ");

        number2 = int.Parse(Console.ReadLine());

        if ( (number2 > 9) || (number2 < 0))

        { number2 = 5; }

        sum = number1 + number2;

        product = number1 * number2;

        difference = number1 - number2;

        Console.WriteLine(" Your sum for " + number1 + " + " + number2 + " = " + sum);

        Console.WriteLine(" Your product for " + number1 + " * " + number2 + " = " + product);

        Console.WriteLine(" Your difference for " + number1 + " - " + number2 + " = " + difference);

        Console.WriteLine(" Thank you for using my basic calculator, " + firstName);

            Console.ReadLine();

        //if ( (number2 <= 9) && (number2 >= 0))

        }

    }

​