Hopefully it should be no surprise that paper is made up of pulp derived from fibers of wood (or sometimes other fibrous materials such as grasses or cotton). These fibers are layered and pressed in a way that means each fiber is positioned in its own unique direction. Keeping this in mind, there is actually a trick when erasing a mistake made with pencil. While a lot of people may move their eraser quickly side to side, or up and down, this is not the most efficient way to erase. The best way is to move your eraser in a circular motion, both clockwise and counter-clockwise. By moving the eraser around in this manner it shifts the fibers of the paper in all directions, which means all of the tiny little fibers can be fully massaged by eraser! Be sure to try this trick next time you need to make a quick correction!