What do those numbers on the publisher's page mean?

Most times you see them numbered 1-10, or 10-1.

Sometimes they skip a number and sometimes they are seemingly random and sometimes they do a little deal like 1 3 5 7 9 10 8 6 4 2 and sometimes they'll skip a number then tack it on at the end (1 2 3 4 6 7 8 9 10 5).

Some older books don't have any numbers at all.

Do these numbers mean anything?