This net is similar to those in my 'Cubes and Things' 3D coloring books, where I use playful patterns to accent symmetries of polyhedra. By truncating one vertex of a dodecahedron, it becomes a tridecahedron. (Do you think truncating all the corners…
This is a standard trihexaflexagon with some extra crease lines. Cut it out and fold it up in the usual way, using tape or glue, adding the extra creases. The new degrees of freedom allow the hexaflexagon to swim along itself like Escher's fish, as…
I have gifted an assortment of laser cut acrylic kits of simple mechanisms, including locks, engines, and other such mechanical devices. These were originally designed as physical diagrams for a book project, but are now being produced for sale.…
The included piece will be a decorated deltoidal icositetrahedron net, which can be colored and subsequently cut and assembled. Alternatively, those with a cutting machine can cut the closed regions on each face of the polyhedron to obtain an…
Years ago, when I first learned of the Temporal Logic system called D, I made a puzzle postcard using the system and mailed copies to a few friends. They seemed to enjoy it, so I'm doing it again, for the Gift Exchange.
A scissors and tape activity on a letter sized sheet of cardstock, for building a horocyclic model of the hyperbolic plane, with a postcard-sized memento of of our sculpture build attached.
Knight mazes are a set of squares on a square lattice upon which a chess knight may move. We examine elements of mazes which can be both attractive and puzzling, and discuss two methods of creating mazes.
Martin Gardner introduced me to Vanishing Area Paradox Puzzles in Aha! Gotcha! with the Vanishing Leprechaun Puzzle. He explained the paradox by describing an old counterfeiting method. I've learned the method and so I'm going to share it with you.…
The puzzle consists of two boxes, with lids, One box is white and the other is blue. Place the white box inside of the blue box and close the lid. Now open the blue box and remove the white box. Next place the blue box inside of the white box and…
My contribution to the gift exchange is a 5 X 7 inch, four-color, tri-fold glossy card with photographed imagery of my 11 X 12 X 9 inch multifaceted-portrait-sculpture of Martin Gardner. My painted, kiln-fired, stained glass and…
Space Chips are a versatile building toy. With the same chips you can build 3D shapes that are symmetrical, or you can build 3D characters that are expressive and creative.
A single two sided heavy page detailing some research on linked circles, space numbers and space logic as a physical gift. In addition a downloaded paper on the same subjects with more details.
My submission is an image featuring six cubes that all look like scrambled Rubik's cubes. But only one is. The other five all have some error impossible to find on a traditional cube. Can you suss out which it is and thereby find The Real Rubik's?
My contribution to the gift exchange is stickers hiding clues leading to a mathematical treasure hunt I'm hosting across my blog and a few other spots on the internet. I also have a physical prize for the first person to reach the end.
In 1909, the Lyon Manufacturing Co. of Brooklyn, NY, published a small advertising booklet for Mexican Mustang Liniment. The booklet contained sixteen Sam Loyd puzzles, most signed with Loyd’s name. Most of the puzzles were duplicates or redrawn…
Sudoku Ripeto and Custom Sudoku are the first Sudoku variants with repeated numbers and letters (please visit www.customsudoku.com). As such, they require new solving tricks and techniques.
I am glad to offer an assortment of books featuring…