Get the Popular Science daily newsletter💡 Breakthroughs, discoveries, and DIY tips sent six days a week. By signing up, you confirm you are 16+, will receive newsletters and promotional content and agree to our Terms of Use and acknowledge the data practices in our Privacy Policy . You may unsubscribe at any time. Long before humans smacked “delete” to obliterate typos, we fixed mistakes and revised written language the old-fashioned way: by rubbing errors clean off the page. The quintessential pink eraser is now a mainstay in household junk drawers, classrooms, and office supply cabinets, but how exactly do these ingenious little pieces of technology work? How do erasers erase? The history of erasers Humans have marked stuff with graphite for thousands of years. However, modern pencils —which encase graphite, or a mixture of graphite and clay, in wood—date back to the 17th century.  Contemporary erasers, meanwhile, came fashionably late. Their precursors include balled-up stale bread and wax.…