Excel has a cell format called "TEXT" that prevents all of these problems. If you plan to use a range of your spreadsheet as text (and not as numbers or dates),

Excel has a cell format called "TEXT" that prevents all of these problems. If you plan to use a range of your spreadsheet as text (and not as numbers or dates), format it as Text and excel will never misinterpret what you type. You can also start the cell entry with a single quote to make a single cell store text.