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Surprise! Puzzles
A small booklet of 20 math puzzles that involve the element of surprise. Some appear to lack sufficient information to solve; others run counter to one's intuition as to what the answer should be.
4 x 13
There are 52 cards in a standard deck of playing cards: four suits of 13 cards each. To design a deck of cards, one needs to establish the four suits, each with its own symbol and/or concept, and find a logic for generating the 13 cards in each suit,…
Rubik's Crew - Pinkie Pie
My Little Pony, 2x2, Rubiks Cube
Lights & Spheres
A 7cm green plastic sphere with a surface of conical projections, otherwise known as a Cando Massage Ball.
Titanium LED keychain flashlights: I will ship 200 with white LED, 100 with red, blue and green LEDs. Each attendee will receive one light…
Titanium LED keychain flashlights: I will ship 200 with white LED, 100 with red, blue and green LEDs. Each attendee will receive one light…
Cavalieri Content Cups
Just as 13 breaks up nicely as the sum of 8 and 5, so too does the (volume of a) cylinder break up nicely as the sum of a cone and hemisphere, a fact we have seen demonstrated at previous Gatherings in vivid ways. But the one-diagram proof of this…
Pattern Stacker
An abstract spatial thinking pattern puzzle
Sierpinski Tetrahedron
A 3D-printed copy of the 5th-level (i.e., 1024 tetrahedrons) approximation of the Sierpinski Tetrahedron.
Please enjoy the beautiful shadows under sunshine.
In particular, this object has projections with positive measure and the shadow contains an…
Please enjoy the beautiful shadows under sunshine.
In particular, this object has projections with positive measure and the shadow contains an…
Build 14 Bridges
The puzzle is strongly related to the number 14.
The trick is based on a pythagorean triple.
The size of the puzzle is about 10cmx10cmx2.5cm, and it is made by MDF.
Goal: Put all bridges on the board.
The trick is based on a pythagorean triple.
The size of the puzzle is about 10cmx10cmx2.5cm, and it is made by MDF.
Goal: Put all bridges on the board.
Modular Space-Filling Tetradecahedra
This Gift Exchange item will consist of four flat pre-cut polyethylene sheets that can be assembled to produce two truncated octahedra with connectors for interlocking into the space-filling arrangement of copies of this polyhedron. Multiple…
The Martian Mayor Problem
The Martian Mayor Problem looks at designing square modular networks which create Euclidean distances between modules. The catch is that there are a limited number of tunnels (connections) between modules. This is a mostly open problem as far as I…
How to Put This Design on an Egg
I have made a full-color, two-sided instruction sheet on how to draw the attached design on an egg, along with a laminated picture of one of my eggs that has adhesive on the back to become a sticker.
Losing Friends with Non-transitive Pip Dice
A pair of standard, pipped, six-sided dice has had its pips painted in three colors. When you roll one of them and count pips of two of the colors, on average, white beats red, red beats blue, and blue beats white. However, when you roll both dice…
Custom Zometool Struts
3D printed custom Zometool struts, and a Zometool ball.
Entropy
Sudoku with some added rules. This puzzle can only be solved in conjunction with the gift "Palindromes" by Elizabeth Gallagher.
Shibori Dyed Hankerchiefs
In anticipation of G4G14, I undertook the mathematical art project of using itajime shibori to dye hundreds of handkerchiefs so that each participant could receive a unique such handkerchief in his or her gift bag. The handkerchiefs represent six of…
Cube-it Puzzle
9 loose square wafers of plastic with a hole in the center of all but one that has a cylindrical pin. It is clear that the wafers can be stacked on the pin. 7 of the wafers have notches of various size in the edges. There are no hints included. Each…
A G4G14 Puzzle
This is a paper ring with a number puzzle. The hint is actually the logo that is at the beginning (which of course will be right after the end when it's a ring).
Zebra Stripe Card
Zebra stripe IBM binary card.
Peace Angel Maze Card
Full color original art maze card of an Angel seeking peace.
Hand of Art Stickers
Two removeable vinyl stickers of the artist's hand.
Troxes
Like Origami meets Lego. No scissors, tape, or glue. This modular paper cutout is based on triangular geometry and mates with neighbors (edge-connecting) to create tetrahedra, octohedra, and icosahedra. The resulting polyhedra can then mate once…
Polarizing Puzzle
Two rectangular sheets that filter light according to polarization- with a twist. Rotating the two sheets ninety degrees with respect to each other results in all light blocked as expected, but flipping over a sheet also gives a similar result. Does…
Akio's Dahlia Star Translucent
I invented the Fibonacci Turbine in an origami way. The wing itself functions as a rotating shaft. The structure is so simple that it is robust. It can be used for many engineering applications.
Palindromes
Sudoku with some added rules. This puzzle can only be solved in conjunction with the gift "Entropy" by Neil Calkin.
Magic Pizza Guy
Solve these puzzles and get a pass to the Magic Castle.