Figuring out where to put all 81 numbers in one of those Sudoku puzzles so that no row or column has any number more than once? No problem. Figuring out how to use 81 nixie tubes for same? No clue!
Username or Email Address
Yes, I wish to receive exclusive discounts, special offers and competitions from our partners.
Now you can get the top stories from Gizmodo delivered to your inbox. Enter your email below.