Hi,

Excel is a spreadsheet and is designed to work with numbers. Its built-in behaviour to interpret your entry this way is something we all just have to live with. To retain the leading zero, you can either format the cell as text before entering the number, or you can preceed the number with an apostrophe, eg '050

If you don't want to see the green triangle warning that the number is formatted as text then you can disable it in the options. I prefer to keep the warning because some worksheet functions will ignore the data (because they are designed to ignore text).