Backing Up To Mitigate File Corruption and Data Loss
Using Windows OneDrive or iCloud (if you are an Apple user) as your default saving location is a good way to mitigate against file loss or corruption. This allows you to set back-ups every few minutes.
When you have finished working on the workbook each day, there are other Cloud storage options, such as Box, Dropbox, Google Drive etc.
It is also an idea to simply email the workbook to yourself at the end of each day so that you have the latest version of the assignment that hasn’t overwritten a previous in case of a corruption.