Real page numbers inconsistencies

Hi everyone, I don't understand how the "real page numbers based on the print edition [some ISBN]" on Amazon are supposed to work.

For example, this book is given as length 242 pages, BUT the ISBN they say it is sourced from is the hardback edition which has 256 pages.

The ebook edition at Goodreads also shows 256 pages.

So if I want to get the most accurate "real" page numbers so I can coordinate with someone else using a paper edition, should I accept the one provided by Goodreads (256) or the one on Amazon (242)?

And why would there be these inconsistencies anyway?

Thanks for any advice,
Tim.