Games and Challenges
Mathematical problems, games and challenges

Creators' secrets
Where do ideas come from when creating a mathematics problem? How can anyone still find original material when so many topics have been explored over the centuries? How do you keep coming up with something new after devising hundreds of problems? How do you entice and engage the reader?

Elegant problem-solving methods (2) | Tangente
The beauty of mathematical problems often lies in an imaginative method—a "haha," as Martin Gardner called it—that makes the solution seem obvious, provided we can find a fresh perspective.

The magic ring of tetrahedra | Tangente
Details on how to build the ring of tetrahedra that you can cut out from the pull-out section of Tangente 200. An explanation of how the numbers on its forty faces were chosen, using a rule that generalizes the concept of a magic square.

Elegant problem-solving methods
The appeal of recreational mathematics is that it requires little formal knowledge. Yet there are ingenious techniques that are hardly ever taught.

Let’s bite into maths: 2021 Fair | Tangente
Get a first glimpse of the programme for the 22nd Culture and Mathematical Games Fair. Held online, it will be accessible to everyone, from anywhere.

The Bernard-Novelli prize: Mathematical news brief | Tangente
Another Tangente Trophy will be awarded this year: the Bernard-Novelli Prize. Run for several years with CASIO’s support, it recognizes a middle- or high-school student—working alone or in a group—who has written a computer program based on a mathematical game.

Radical-X: combinatorics in play | Tangente
Radical X is a compact game packaged in a rectangular box with edges measuring less than 5 cm.

Reference books on Conway | Tangente
Guided by his passions and discoveries, John Conway wrote many fascinating books, regrettably few of which have been translated.

Conway, the game-playing mathematician | Tangente
John Conway advanced finite group theory, number theory, topology, theoretical physics, combinatorial game theory and geometry. His originality, creativity and extraordinary personality made him popular with mathematical game enthusiasts everywhere, especially after he created the Game of Life in the 1970s.

In logic and combinatorics
In mathematical and logical puzzles, often inspired by observations of everyday life, polynomials can crop up in surprising ways. Geometry, binary logic and algorithms, peg games, combinatorics… no field is immune!

Randomness in video games
ChickenPods is a free-to-play video game (F2P to those in the know) developed in 2019 at the startup Mathilde. Randomness plays an important role in generating environments and determining how the chickens move. That is where mathematics comes in...

Philippe Charbonneau: mathematical sculptor | Tangente
The artist Philippe Charbonneau (1936–2019), well known to Tangente readers, died a few days after the Mathematical Culture and Games Fair, which he had attended.

Intellectual self-defense: zetetics courses | Tangente
Cortecs (Collective for Transdisciplinary Research on Critical Thinking & Science) is a teaching and research collective founded in 2010 to produce educational resources and scientific content, as well as courses and training in critical thinking, intellectual self-defense, zetetics and the scientific method.

Bernard Novelli, master of logic puzzles | Tangente
No Tangente feature on mathematical games would be complete without acknowledging the role Bernard Novelli played on our magazine's team (see Tangente 141, 2011)

In the press too…
Mathematical games, familiar from the scientific press, are few and far between in the mainstream press. Some newspapers have nevertheless taken the plunge, often with success! There is indeed an audience for recreational mathematics—provided it is not schoolwork in disguise.

Claude Mydorge:
A keen enthusiast for geometry, Claude Mydorge collaborated with René Descartes. His interest in conic sections led him to study the laws of optics and astronomy. He also developed a particular fondness for mathematical games and recreations.

AI for training | Tangente
The training landscape now includes a wide range of stakeholders. AI can be used in many ways, both in schools and in the workplace.

Ethical driving - mathematics brief | Tangente
Programming self-driving cars raises ethical questions. Unexpected new conundrums have emerged. Some require only minor adjustments, but others remain unsolvable for now.

The magic of domino divisibility tests
You know the divisibility tests for 2, 3, 4, 5, 10, 20… and perhaps others as well. But are you familiar with "domino tests"? Variants of a famous divisibility test for 11, they make for a wonderful mathematical playground!

Build your mysterious crystal: patterns & assembly | Tangente
The Mysterious crystal—actually the first stellation of the rhombic dodecahedron—can be built from six identical pieces. Whether you use scissors, a cutting machine or a 3D printer, choose whichever method suits you. The hardest part is working out how to assemble them.
