How can I stay sane doing very boring work?

For the next two weeks or so, before I go back to college, I’m working basically as many hours a day as I can handle from home scanning files for my mother’s law practice.

I really do need the money to save up, but I’m struggling to do more than four or five hours a day without losing my mind completely. She’s willing to pay me for as many hours as I can do, and she pays $15/hour, so obviously I want to maximize my working time.

How can I woke more without losing my mind from the sheer drudgery of it?