The Hundred Hunt is a free visual challenge inspired by Rob Walker's The Art of Noticing and a 1970s exercise by designer George Nelson. Find and photograph every number from 1 to 100 in the real world — on doors, sidewalks, fire hydrants, anywhere they exist. Log each find with a photo and location. Watch your grid fill in slowly. Featured in Rob Walker's The Art of Noticing newsletter. Free, no account required to start.