The best way to organize our calculator is to use a wxGridBagSizer. Our buttons will almost be the same size and will be organized in rows and columns, so a wxGridBagSizer is perfect for the job. The wxGridBagSizer is also pretty simple to use, so that's another plus.

Our calculator isn't going to be very complex, as I mentioned before. On the first row of our calculator will be the display, which will be served by a read-only wxTextCtrl. The display will take up the entire row. The second row will contain the add to memory button, a button for the number one, a button for the number two, a button for the number three and an addition button. The third row will contain a delete from memory button, a button for the number four, a button for the number five, a button for the number six and a subtraction button. The fourth row will contain a memory recall button, a button for the number seven, a button for the number eight, a button for the number nine and a multiplication button. The fifth row will contain a wxStaticText that displays the number currently in memory, a decimal button, a zero button, a solve button and a division button. The final row will contain a two-column clear button, a backspace button, a positive/negative button and a square root button.

We'll save ourselves the pain of creating over a dozen methods by making use of event ID numbers. I'll show you how to do this once we're at that point.

Let's get to it.