The same is true for my students (german school system, iPads form 7th to 13th grade): They are marking, annotating and rearranging parts of the digitized pages as they like. It would be impossible with printed books.
(ok, they could take a picture with the camera and do the same)
They have/use printed books but most of the students are borrowing them from the school and are not allowed to write in them.
So I use mostly digital material and most of the books stay at home for studying (the books are heavy).
So I use mostly digital material and most of the books stay at home for studying (the books are heavy).