The e-ink pages on a Kindle’s display does not, in general, contain the same number of words as a book page printed on paper. As you might expect, this means that turning an e-page or two (or three) may correspond to the same paper page number.
I was slightly surprised to see, however, how paper page numbers was actually implemented. The default reading progress indicator remains Kindle’s notion of location (e.g., 1452 of 7680) and percentage complete. Paper page numbers are not displayed unless the reader presses the Menu button. Only then is the current page number and total page count visible (see the screenshot on the left). This is an acceptable compromise in return for a relatively clutter free page bottom. However, I suspect anxious students instructed to “read pages 40 to 60″ may be pressing the Kindle’s Menu button quite often.