Games and Challenges
Mathematical problems, games and challenges
666: When the devil shows up in math | Tangente
From the biblical 666 to the Belphegor number, certain numbers send a shiver down the spine… and bring a smile to mathematicians' faces. Behind these "cursed" objects, the creativity and ingenuity of recreational mathematics run wild, ranging from number games to diabolical curiosities.
Three cheers for France! | Tangente
The international final of the Mathematical and Logic Games Championship was held on August 23 and 24. This year, it took place in Mahdia, Tunisia.
Math games: 2048 and more | Tangente
All right… a little screen time after all—not to do the arithmetic for us, but to practise mental arithmetic while having fun. The games featured on this page can be downloaded to a smartphone.
Mathemagical interview with Yves Meret | Tangente
Yves Meret teaches mathematics at Lycée Blaise Pascal in Rouen, but he is also a magician. Here he tells us how he lives out these two passions, which he has turned into his profession.
A panorama of set theory | Tangente
Work on the notion of infinity led to paradoxes. This forced mathematicians to formalize set theory. Progressive axiomatization led to the current ZFC system, which nonetheless remains subject to various shortcomings following the work of Kurt Gödel and Paul Cohen.
Four mathemagic tricks
Martin Gardner knew how to blend magic and logic to captivate his readers. A tireless seeker of magic tricks, he explored the "27-card trick" in particular, and created many others besides.
Martin Gardner: Itinerary of a genius | Tangente
Although he is known for his recreational mathematics and his work as a popularizer, Martin Gardner strangely never pursued a course of study in the discipline. Here are the surprising stages of his unusual path.
Recreational problems from the Arab-Islamic world
Mathematical recreations feature prominently in the Arab-Islamic tradition, yet they do not appear to have been collected in dedicated anthologies. Some examples, very well known in Europe, pose a real challenge to historians seeking to trace how they circulated.
Conjectures finally settled! | Tangente
New developments in the famous "moving sofa problem" and advances in triangle dissection.
Cyril Bonin's universe: comics and mathematics | Tangente
Mathematics can hold a special place in an artist's thinking. Cyril Bonin explains how: he is the sole creator—writer, artist and colorist—of a distinctive body of graphic novels.
GIMPS and Mersenne primes | Tangente
If you would like to put your computer to work for research, your name might one day be associated with the discovery of a new Mersenne prime…
The joy of mathematical discovery: amateur mathematicians | Tangente
Christian Boyer, Vincent Thill, Jean Moreau de Saint-Martin and Philippe Fondanaiche—all passionate amateur mathematicians—agreed to answer our questions about how their interest in mathematics began and the activities they have developed in their favorite areas.
The mathematicians of Père-Lachaise | Tangente
At this time of year, around All Saints’ Day, tradition calls for visits to cemeteries. So let's take the opportunity to visit the graves of mathematicians in the most iconic cemetery of all: Père-Lachaise.
A cork on the river | Tangente
Set a cork adrift on the surface of a river. When its path is too difficult to calculate, approximation methods are the only option. Sometimes, however, the way the water flows makes the reliability of such methods problematic.
Combinatorics on words and music | Tangente
Combinatorics on words is an area of mathematics that has proved particularly fruitful for studying certain musical phenomena, especially the rhythmic features of African and Malagasy music—so much so that a computer can even recreate them!
The turtle algorithm in Vanuatu | Tangente
Mathematical modelling offers one way to make sense of Vanuatu's sand drawings. In particular, it will lead us to a surprising "turtle theorem".
Laurent Schwartz, politically engaged mathematician | Tangente
The publication of the graphic novel Laurent Schwartz, les engagements d'un médaillé Fields offers an opportunity to revisit the life and struggles of this surprising mathematician.
The egg equation | Tangente
Three researchers, Valery Narushin, Michael Romanov and Darren Griffin, recently published a paper proposing a general formula for drawing the outline of any real egg.
The man of fractures
For millennia, straight lines, circles, parabolas, and other smooth surfaces had reigned supreme and unchallenged over geometry. Then Mandelbrot unleashed the "mathematical monsters" of the early 20th century, transforming our picture of the world forever.
Penney's paradox explained | Tangente
Does tossing a coin strike you as simplistic and dull? Be careful, though: it has some baffling surprises in store!