Working with large and complex Excel workbooks, especially when entering large amounts of data, no one is protected from accidental changes in formulas, formats and other spreadsheet elements. But you can protect yourself from too much work on finding and eliminating such errors by protecting the individual spreadsheet elements.

Excel offers you an ability to assign user-level permissions to different areas on a protected spreadsheet. You can specify which users can edit a particular range while the spreadsheet is protected. As an option, you can require a password to make changes.

You can significantly reduce the number of errors in data entry in Excel by protecting changes of specific spreadsheets (worksheets) and cells.

The Excel TEXT function enables you to specify numbers and date format.