# Browse Items (51 total)

- Collection: G4G14 Exchange Bag

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## 14 Rabbiducks

The puzzle is to fit 14 “rabbiduck” polyomino pieces into an 8x11 rectangle. (Gardner wrote about polyominoes in multiple columns. The specific polyomino pieces used are inspired by the rabbit/duck illusion that Gardner called the Rabbitduck in his…

**Tags:**
G4G14, Puzzle, Recreational Math

## 14-sided and Skew 8-sided Dice

A fair 14-sided die in the form of a heptagonal trapezohedron and a fair 8-sided die ("Skew d8") in the form of a triangular dihedron.

**Tags:**
G4G14, Recreational Math, Toy

## 4!-Fold Puzzle

Are there any polycubes that can be unfolded into exactly a rectangle? This problem was solved in 2019. The smallest solution forms a nice puzzle — fold the rectangle into a polycube!

**Tags:**
G4G14, polycube, polyominoes, Puzzle

## A "Pick a Card" Card

A card (roughly the size of an index card) with an image that contains 54 playing cards (some duplicates, of course!). A spectator chooses one of the playing cards and, after a few questions, the magician reveals the choice!

The premise is similar…

The premise is similar…

**Tags:**
G4G14, Magic, Recreational Math

## 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).

**Tags:**
G4G14, Puzzle, Recreational Math

## A Torus Without Diagonals

Cut-and-fold a polyhedron with 7 vertices, 14 faces, 21 edges, and a hole through it like a doughnut. A cube has internal diagonals that connect the diametrically opposite corners. By contrast, this polyhedron has no internal diagonals. There are…

**Tags:**
G4G14, Puzzle, Recreational Math

## Abstract Photograph - Acura TL

One of my interests is abstract photography, using ordinary photographs as the “paint” and using spatial and mathematical transformations to create an image from one or more sources. One transformation that I’ve been exploring is “Inside Out”, which…

**Tags:**
Art, G4G14, photography, Recreational Math

## 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.

**Tags:**
Exchange Gift, G4G14

## C.L. Dodgson (Lewis Carroll) Oxford Mathematician

Lewis Carroll, the nom de plume of the Rev. Charles L. Dodgson, a mathematics lecturer at Oxford, was also an innovator in recreational mathematics, magic, puzzles, cryptography, and inventions. His appearances in Scientific American began with…

**Tags:**
G4G14, Recreational Math, Word Play

## Flippe Top

This document describes how I designed a new kind of top, which flips not just once, but over and over. I call it a "flippe top". It can be made either from wood or by 3D printing.

**Tags:**
3D printed, G4G14, Toy

## G4G14 Exchange Gift (Martin Gardner Magic Trick)

We, on behalf of ThinkFun, would like to submit a physical gift based on a personal letter sent from Martin Gardner to one of our founders, Bill Ritchie, in 1994. We will submit photocopies of the letter, which describes how to perform the magic…

**Tags:**
G4G14, Legacy, Magic, Recreational Math

## Golomb Rulers

A perfect ruler for daily use. In mathematics, a Golomb ruler is a set of marks at integer positions along a ruler such that no two pairs of marks are the same distance apart.

**Tags:**
G4G14, Recreational Math

## 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.

**Tags:**
Art, G4G14, Recreational Math