what software are you using and how is the class structured? It sounds like this might be a rotating group of students all using the same ipads? Does the school have access to some sort of storage medium that requires unique (per student) login credentials that the students could save their files to?
Honestly, pretty effective, I used to balance the mattresses on my head when working in a dorm. Many societies used this approach to move things, and with three of them the have the definition of a geometric plane.