Take 25 or so file folders and fold a posterboard in half. Glue one file folder on the top of the posterboard. Continue to lay the file folders on top of each other leaving the tab showing. When you are done, you should have 25 pockets to fit papers in. Label the tabs with student's names. Lay it flat somewhere in your room that the children can reach. I teach my children how to file their own papers throughout the day. As I grade or check papers, I then return them to that child and they file it themselves. I never have to file one paper! On Fridays I pull the papers, staple them together, and put them in a pocket folder to go home on Mondays.