Cross Every Bridge Once: The One-Stroke Town Puzzle

Cross Every Bridge Once: The One-Stroke Town Puzzle is a free, online competition on the IQ GradeUp platform for students in KG 2 through Class 12. Entrants design a fictional town with exactly five named locations and seven bridges or paths, arranged so one continuous journey crosses every bridge exactly once without repeating a bridge. The entry must present the unsolved puzzle first, followed by a numbered solution and a clear explanation of why the start and finish locations work. The map must have exactly two locations with an odd number of connected bridges, a clearly identified starting and finishing location, a numbered route showing all seven bridges crossed in order, and a final check confirming every bridge appears once. Entries are submitted as one PDF of no more than two pages: page 1 is the clean, unsolved puzzle and page 2 is the numbered solution route and explanation. The competition runs from 6 November 2026 to 14 November 2026. Judging is based on mathematical validity and a verified one-stroke solution (35%), elegance and challenge of the network design (25%), clarity of the puzzle map and solution route (20%), quality of the start-and-finish explanation (10%), and originality, accessibility and rule-following (10%). No prizes are stated on the competition page.