Before erasers were invented, people used rolled-up pieces of white bread to wipe away pencil marks.

Pencils became popular after a huge pile of graphite was discovered in Borrowdale, England, in 1564. For the next 200 years, writers and artists kept a loaf of bread nearby to fix their mistakes. They would take the crust off and roll the soft center into a small ball.In 1770, an engineer named Edward Nairne made a lucky mistake. He reached for a breadcrumb but grabbed a piece of dried sheep-tree sap instead. He realized this new material worked much better than bread and didn't rot.That same year, a scientist named Joseph Priestley gave the material its name. He called it 'rubber' because it could rub out marks so easily. Before this, the material was mostly known as 'gum elastic.'Modern erasers work using friction. When you rub an eraser on paper, it creates a tiny bit of heat. This heat makes the eraser sticky enough to grab the graphite particles. The graphite is then lifted off the paper fibers and trapped in the little eraser crumbs you brush away.