For the record, MLA/APA now officially recommend using chapter/paragraph citation methods when citing an ebook.
If it's good enough for them, it's good enough for your students...
Some ebooks do come with page-mapping data e.g. Kindle's "real page numbers" (
APNX) or the EPUB
Page-map /
PageList.
Note: Many EPUB ereaders will lie and use the Adobe Digital Editions "2048-characters-is-a-page-by-fiat" if no page mapping exists.
calibre can be set to sideload pseudo-random generated page numbers if sideloading books to a Kindle via calibre (I believe this is the default) -- be careful.
When Real Page Numbers for Kindle books exist, Amazon's product page will specify the ISBN of the paper book it matches.
MLA/APA suggests using Real Page Numbers
when they exist.