The sheer number of books about mathematics published each year never ceases to amaze—and delight—us! The Tangente Prize was created to help the public navigate this wealth of material. The announcement of the award is now eagerly followed by publishers and booksellers alike. The process has two stages: an online vote during the summer selects five books from the ten shortlisted by the Tangente Club team; a jury of experts then chooses the lucky winner.
Two changes were made this year to the way the prizewinner was selected: first, only subscribers to Tangente and members of the Tangente Club could take part in selecting the five books eligible to compete; second, they could vote for two books rather than just one, as in previous years.

Claire Lommé's book, winner of the 2023 Tangente Prize.

The Tangente Prize has its first female winner! -----------------------------------------
The Tangente Prize jury met with one guiding principle, as stipulated in the rules: to honor a book "that has inspired a broad readership to learn more about one or more areas of mathematics". After carefully reviewing the competing books, the jury had no hesitation in awarding the prize to Claire Lommé for Vous reprendrez bien un peu de maths ? (Retz, 2022). In a series of entertaining entries, the author presents various aspects of mathematics and their connections with the real world. The jury appreciated the freshness of the writing by a teacher and teacher trainer whose love of mathematics shines through, along with her desire to share it. The book clearly explains such concepts as the distinction between "digits" and "numbers," the birth of zero, and different approaches to infinity. Claire Lommé gives precise definitions of properties such as alignment and the right angle. The book skillfully looks at everyday life through a mathematical lens. The quality and relevance of the illustrations add to the appeal of this book, which is accessible to a very broad readership. Finally, Claire Lommé is the first woman to win the Tangente Prize.

Claire Lommé.

The trophy is a work of fractal art created

by mathematician and visual artist Denise Demaret-Pranville.
The jury also wished to recognize two other books published over the past year by awarding them honorable mentions. One went to Yan Pradeau for La Guerre des nombres premiers (Flammarion, 2023). The book takes an original approach to the development of our knowledge of prime numbers, from antiquity to the present day. It brings the leading figures behind these discoveries to life through episodes from their lives. Another honorable mention went to 21 énigmes pour comprendre (enfin) les maths (Albin Michel, 2022) by Antoine Houlou-Garcia, winner of the 2019 Tangente Prize, and Thierry Maugenest. The puzzles are short, while the clear, well-supported answers encourage reflection. The jury particularly appreciated the sociological and philosophical dimensions. Its only regret was the title, which does not quite reflect the book's content.
The Affaire de logique prize --------------------------
Under the auspices of Tangente and the Tangente Club, the annual problem-writing competition was once again launched in partnership with the Association des professeurs de mathématiques de l’enseignement public (APMEP) and the recreational mathematics website Diophante.fr, attracting many entrants. The competition culminates in the "Affaire de logique" Prize, echoing the weekly column of the same name that Élisabeth Busser and Gilles Cohen wrote for more than twenty-five years in the daily newspaper Le Monde, with Jean-Louis Legrand joining them more recently (see In brief: the "Affaire de logique" column). This prize, too, is awarded during Tangente Day.
This year's many submissions covered several categories: numerical problems; logic; mathematical curiosities; and geometry. The prize went to François Delannoy, who describes himself as a "collector of mathematical curiosities": he collects surprising theorems and scientific objects! This mathematics teacher and workshop leader, based in the Oise department, had already received an honorable mention for a problem he created for the competition marking Tangente issue 200. The winning problem, "A Rolling Glass Gathers No Moss", concerns geometry; like the other problems honored during Tangente Day, it appears in the "Problems" section of this issue. François Delannoy says he drew inspiration for his problem from the motion of a twirling baton rolling along the ground. The jury unanimously recognized the problem's originality and straightforward wording.

François Delannoy, author of the problem "A Rolling Glass Gathers No Moss," with his trophy, created by the Scowcza vector-art collective.

A first honorable mention went to Marc Foubert, an engineer who enjoys putting mathematical puzzles into words and giving them a playful setting. His logic problem "Sand Walls" was apparently devised during walks along the beach. In it, a keep and towers are built at the vertices of a square grid whose cells are one foot wide. Not only was the problem's author delighted to receive his award, but his grandfather Philippe Fondanaiche, founder and editor of the Diophante.fr website, was at least as delighted as he was.
A second honorable mention went to Daniel Collignon, a statistical engineer who says he discovered mathematics competitions—and began to enjoy the subject—through the Fédération française des jeux mathématiques. His numerical problem, "A Quick Résumé", was inspired, he says, by his own age and those of his children, which the statement requires to be expressed as whole numbers of years. The problem may look conventional, but it involves an interesting piece of arithmetic reasoning.
The best article prize ---------------------------
Finally, the Best Article Prize is awarded to a popular mathematics article written "in the style of Tangente." The winning article, Euler's Formula, will be published in Tangente shortly. Its author, retired engineer Christian Rivière, is interested not only in mathematics, of course, but also in linguistics, statistics and quantum computing. The article tackles a classic subject, which he has managed not only to present engagingly but, more importantly, to take beyond three dimensions. The author's original idea requires a certain capacity for abstraction, but is presented and illustrated highly convincingly. You will soon have the pleasure of reading the article in our pages!

Christian Rivière, author of the article Euler's Formula.

He receives a work of fractal art created by Sandrine Vivier-Souder.
An honorable mention also went to mathematics teacher Nathalie Braun for her article Mathematical Simplification. The "simplification" in question is that of an algebraic expression, sometimes a sophisticated one. Despite the subject matter, the article is engagingly written, with numerous references to… gastronomy (!), which hold the reader's attention to the very end and show an enjoyable way to do mathematics—but shh, without ever saying so!
Roll on the 2024 Tangente Awards, when we can all discover what our ever more inspired readers will cook up to share their passion for mathematics!