I asked this 4 years ago and did not find out until today that somebody had responded. but nothing in that answer helped. I still produce some 75 papers annually that I distribute to hundreds, sometimes thousands of people and never have been able to number the pages in any of the papers!
that response said - "… Chapter 4 of the Starting Guide (Getting Started with Writer) has the answer to your problem. As also does Help, INDEX > page numbers > inserting/defining/formatting. On my system (LibO 5.1, EN-GB, Linux-Mint Mate 17.3) it is useful to provide background information, I need to place the cursor where I want the page number then to select INSERT > PAGE NUMBER > then follow through on FIELD or HEADER/FOOTER.
But I don’t know where to find the "Starting Guide (Getting Started with Writer). Help doesn’t give anything except a notice that help is not installed on my computer… no info about where to find it online or how to install it on my computer. I have no idea what background information would be helpful, but the example in his parenthesis is all gobbledegook to me… and I cannot find out what version I have anyway. Oh I use Windows 10 because that is what came installed in the computer I purchased 3 years ago. Or was it 5 years ago???
As to his final sentence, " I need to place the cursor where I want the page number then to select INSERT > PAGE NUMBER > then follow through on FIELD or HEADER/FOOTER." - what??? wait, so that means that I must go to each page and adjust so there is room at the bottom of the page and put in each number one page at a time? that is insane! there must be a way to tell the document to put page numbers on all the pages, in order, at the same place on each page… whichever it or I choose.