help numbering in indesign

I want to number pages 01/10 having the 01 updated per page and the 10 showing the total number of pages in doc. Can I do that? I would like to creat multiple docs from the same master page setup so some docs may have 5 page total or 50. Can that second number sutomatically update on the total of pages? Like if I have 10 pages, I can put 10 in the master. Howver, if I delete a page I have to go in manually and change each to 9