I'm learning C#. (6 hours in) I'm more comfortable with Ruby and Javascript and am finding C# fun, yet way tighter in what it will allow you to do, so I am rediscovering simple functions. I'm trying to build a simple calculator just to transition to the C# way of doing things and I keep hitting scope issues. 

Here's the code. The NumSelect function is breaking it. I want a user to be able to type in 2 numbers in the console and then they'll be added. Once that works I'll create other math operations and throw in some logic to have the user select with operation they would like to do and then ask them for their inputs and then do the calculation.

The error is 

```
calculator.cs(18,9): error CS0103: The name `number1' does not exist in the current context

```

and it's hitting it at very instance of number1 and number2 beyond the NumSelector function. So it seems like a scope issue, but I can't figure out the right approach for assigning these variables in a function so I only have to do it once.

```
using System;

class SimpleMath
{
    public int Add(int number1, int number2)
    {
        int result = number1 + number2;
        return result;
    }
    public int Subtract(int number1, int number2)
    {
        int result = number1 - number2;
        return result;
    }
    //this function will assign the inputs to variables
    public int NumSelect()
    {
        number1 = Console.ReadLine;
        number2 = Console.ReadLine;
    }
    static void Main()
    {
        SimpleMath operation = new SimpleMath();

        Console.WriteLine("Give me two numbers and I will add them");
        operation.NumSelect();
        int result = operation.Add(number1, number2);
        Console.WriteLine("{0} + {1} = {2}", number1, number2, result);

    }
}

```