IMPORTANT NOTE: Regarding Gift Exchange Copyright

In the spirit of Martin Gardner, who believed in inclusiveness and the sharing of knowledge and curiosity, and as a non-profit that benefits from the generosity of our community, G4G is pleased to give back to the world by making the G4Gn Gift Exchange Books available for download online.

However, these papers are a compilation of original material and the contributors retain their copyrights. No part of the Gift Exchange Books may be reproduced or distributed in any form, without prior written permission from the original author. If you would like to request permission to reproduce or alter any G4G paper, please contact and we can put you in contact with the author.


Bob Hearn — G4G12 Schedule



Vladimir Bulatov — 3D Printed Fractal Pendant
Vladimir Bulatov — Making Fractal Pendant in ShapeJS
Mark Burstein and Jim Gardner — Cover Drawing
Gwen Fisher — Topologically Interesting Felt
Pedro Jorge Freitas and Simão Palmeirim Costa — Almada Negreiros and the Geometric Canon
Lew Goldklang — Coffee Vapor
Lew Goldklang — Coffee Vapor Cropped
Lew Goldklang — Clouds in my Coffee / Pattern Recognition
Fred Henle — Space-Filling Curves on Non-Periodic Tilings
Margaret Elizabeth Kepner — Custom Card
James Lee — Menger Sponge in Mathematica
Alexa Meade — Up Down Coin
Alexa Meade — Double Take
Robert Orndorff— Folding Method for “OSU Triptych No. 2”
Norton Starr — Greek Cross Puzzle



Kate Jones — Celebration of Mind 2015
Kate Jones — Gamepuzzles!
William Liles — Fair Poker with Marked Cards
Robert Morrill — Black or White



Hirokazu Iwasawa — Magic Math Puzzles
Doron Levy — Two Person Telepathy



Adam Atkinson — The Samaritani Formula – More Details
Nancy Blachman — Saint Mary’s Math Contest Qualifying Problems
Kenneth Brecher — The “PhiTop”: A Golden Ellipsoid
Paul Clarke — Breaking Squares and Cubes
Jill Cochran, Eric McDowell and Ron Taylor — Roots of Polynomials with Fibonacci Coefficients
Stephen Fenner, William Gasarch, Charles Glover and Semmy Purewal — On the Border Between Recreational and “Serious” Mathematics
Susan Goldstine — Hexalfexagons and the Other Feynman Diagrams
Rik van Grol — Speed Cubing
Richard Guy — The Leaning Tower of Pingala
George Hart and Elizabeth Heathfield — Making Math Visible
Akio Hizume — Fibonacci Pavilion
Louis Kauffman — Two Math Fables
Louis Kauffman — The Quaternion Demonstrator
Robert Munafo — Analogue Approximation Finder
Eleftherios Pavlides, Thomas Banchoff and Sarah Thompson — Hinge-elastegrity’s Shape-shifting
Dogon Rokicki — Larger Golomb Rulers
Michael Tanoff — Philatelic 12s for G4G12
John J. Watkins — Trapezoids, Primes, and Cousins



Kate Jones — Twelveness
Kate Jones — The Playable Art of Kate Jones
Louis Kauffman — Self-Description
Peter Renz — Martin Gardner and Scientific American



George Bell — A 12-Loop 4 G4G12
David Cohen — 12 Flower Puzzle
Erik Demaine and Martin Demaine — Secret Messages in Juggling and Card Shuffling
Yossi Elran — The 100 Prisoners Puzzle Revisited
Andrea Gilbert — Collection of “Step-over” Logic Mazes
Markus Goetz — Mini Folding Puzzles
Chaim Goodman-Strauss — dimerMRTiling
Bill Gosper — Neil Bickford™s Space Cube
Emrehan Halici — Five Problems
George Hart — Hinge-a-Tron
Bob Hearn — A Trio of Coin-Jumping Puzzles
Dick Hess — Puzzles and Recreational Math
Carl Hoff — Abstract
Carl Hoff — Wrap O-round Weave 5, or WOW5
Carl Hoff — Carl’s Puzzles
Wei-Hwa Huang — Masyu and Yin-yang Puzzles
Lyman Hurd and Jay Schindler — Euler Polyominoes
Peter Knoppers — Martin Gardner Modular Origami G4G12 Rhombic Dodecahedron
Peter Knoppers — Abstract
Peter Knoppers — 12 Sheets
Robert Lang — DeZZ Unit
Roy Leban — Cubes for G4G12
David Leschinsky — Eureka’s General Thinking Processing Chart
Daniel Levy — Perplexing Puzzle Poem in Pentameter
George Miller and Nick Baxter — The Mystery of The Calibron Twelve Block Puzzle
Chris Morgan and Jeremiah Farrell — The White Rabbit 12-Puzzle
Stuart Moskowitz — Which Man Disappears?
Pradeep Mutalik — How Puzzles Made Us Human
Pradeep Mutalik — The Sleeping Beauty Paradox Resolved
Erika B. Roldan and Martinez I. Pérez — The Mutando of Insanity
David Singmaster — About Puzzle Grills
Ryuhei Uehara — Jangrams, Polygons Folding to Three Boxes
Frans de Vreugd — Incredible 18 Piece Burrs



Shannon Lieb and Jeremiah Farrell — The Jing and Jang of Quantum Physics Truth Tables