Math Recreations
Mathematical recreations: enigmas and fun puzzles

In search of the missing squares | Tangente
There is no need to invoke the paradoxes of infinity to have fun with areas: a simple rectangle is enough to create some formidable puzzles! All you need is a sheet of paper, some pencils, a ruler and a pair of scissors—and you are ready to make little squares disappear.

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.

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!

Paris, the capital of mathematics competitions, 2018 | Tangente
Following the Kangaroo awards and the national Olympiad prize ceremony, and with the International Mathematical Games Championship final still to come in August, Paris hosted the International Tournament of Young Mathematicians in early July. This international mathematics research competition for high school students was first launched in the French capital in 2003.

The mysterious crystal
For a change, beneath its polyhedral exterior, the subject of this instalment in our mathematical objects saga is a puzzle. You will find everything you need to build it on the Tangente website.

The tippe top: a mystery of mechanics
In playgrounds, the tippe top is often called a "magic top" because it flips itself over, turning upside down. Its counterintuitive behavior is subtle...

2018 Championship
The 32nd Mathematical and Logical Games Championship, organized by the Fédération française des jeux mathématiques, is under way. Tangente brings you an exclusive look at the eighteen problems from the individual quarterfinals.

Raymond Smullyan (1919–2017): logician and magician
An eclectic mathematician, Raymond Smullyan, who died last June, was best known to the general public for his books of mathematical recreations centered on logic.

Numbers in a triangle: math puzzles to explore
The arrangement of numbers in Pascal's triangle obviously lends itself to play, and many mathematical recreations refer to it.

Bachet and Bézout: a winning mathematical duo
From Gauss's lemma to the Chinese remainder theorem, by way of numerous Diophantine equations, no problem seems able to resist the Bachet–Bézout theorem. Games, recreational puzzles, arithmetical tricks… Let's dive into mathematics!

Salon 2016: maths transform our society | Tangente
The unmissable Salon Culture et Jeux Mathématiques will run from Thursday 26 to Sunday 29 May on Place Saint-Sulpice. Save these dates for the (free) mathematics event of the year!
