How do I recover lost information in Numbers?

Numbers autosaves. You do not need to explicitly save a document when you close it.

If you are on a Mac and you are able to open the file but your data is gone then you might have some luck by going to File > Revert To.

If you have backups via Time Machine try there.

Another thing to try is going to Numbers in iCloud.com, opening the document, clicking or tapping the circled three dot icon and choosing the option that allows you to view versions.

SG

Hi dreda,

From Save and name a spreadsheet in Numbers on Mac – Apple Support (AU)

The first time you save a spreadsheet, you name it and choose where to save it — on your desktop or in a folder, for example. After that, Numbers automatically saves your spreadsheet as you work.

That is, you must save at least once for autosave to work.

Regards,

Ian.

Did you save the file? If you close a file, if you haven't saved it, the content will be gone.