Ereader VS Physical Copies

I have begun to learn while reading Nightshade that if you want to go back and forth from an ereader to the actual book your pages not all line that well. Nightshade book is over 500 pages or so long the ebook is only 290 pages long. So I have had to go from chapter to chapter in order to switch.

Thus making me take a bit more time to finish it.