Numbers app

That is enough of an explanation, thanks. If you recently updated the Numbers app on the iPad, the Export option has been moved to the menu under the Spreadsheet name on the top left side of the app. Tap on the small downward arrow there.

Why not?

What happens when you try?

How are you trying to send the Spreadsheets in PDF? What steps are you following?

Explain the issue you are having in as much detail as possible, and someone may be able to help.