How to “close” a Numbers spreadsheet in iPad

I had the same question. I ran across an old thread which did not answer the question but recommended strong Password Managers. Again - THIS DID NOT ANSWER THE QUESTION.

As I tried various buttons I discovered that pressing the “directory / files” button (top left corner, above the Numbers name) appears to clear the spreadsheet and present a view of files available in a certain directory (very similar to the Files application).

If someone has another solutions / something better, I am interested.

Thanks,