Mathematical Themes
Explore the major mathematical themes: geometry, algebra, analysis, arithmetic, logic, and many other fascinating fields.
Con your friends with maths and logic | Tangente
discover how mathematics can help you outwit con artists
Ponzi schemes
Pyramid investment schemes, which pay early investors with funds contributed by later ones, have shown their limitations. They can be modeled. Curiously, however, some government practices are not so very different from these models…
Maths for the taxman | Tangente
Algorithms are used to cross-reference data from several sources and assess the plausibility of a tax return.
Scams, fraud, hoaxes, deception… and mathematics
Archimedes’ example shows that mathematics was once used to expose fraudsters’ tricks. Is that still often the case today? More often than not, no.
Soroban and Japanese human calculators | Tangente
Practising the Japanese abacus is considered an art in Japan, where, as in judo, practitioners progress through kyu belt ranks and then dan grades.
An innovative new kind of calculator | Tangente
The French company Numworks has joined the select club of calculator manufacturers. This new machine is based on open-source principles.
Calculators in entrance exams: end of an era | Tangente
For several years now, some written papers in the competitive entrance examinations for France's engineering grandes écoles have prohibited calculators. But this was not a blanket rule.
Numeracy: an asset for life | Tangente
Being able to estimate large numbers, calculate a proportion, understand a percentage, convert currencies, or simply perform basic arithmetic without the help of a smartphone or calculator is essential in everyday life. Yet innumeracy is on the rise.
Learn to calculate with a calculator | Tangente
Machines generally calculate faster than people. But exactly how does a machine perform a simple addition? Revisiting the methods taught to children reveals two main techniques, which we can compare using CASIO's Graph 90+E calculator.
Fast calculation with the Trachtenberg method | Tangente
You may have heard of the "Trachtenberg method" in the recently released film Mary. It is an iterative method for performing impressive mental calculations with large numbers.
The mechanics of calculation
To calculate faster and more accurately, humans created devices as ingenious as they were varied! It can be hard to imagine that, only a few centuries ago, machines were expensive and cumbersome. Sophisticated calculations were therefore the preserve of an elite.
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!
Geometric “tricks” for arithmetic
The human mind often needs concrete representations of abstract concepts. Geometry can thus serve as an aid to calculation, as Descartes was among the first to show.
Mental arithmetic: a vital skill | Tangente
There is unanimous agreement: mental arithmetic is fundamental both to mathematics education and to citizens of tomorrow. What lies behind this remarkable consensus, and where does mental arithmetic stand in schools today? Let's take stock.
The Bohemian dome
You are certainly familiar with the torus, obtained by rotating a circle about an axis lying in the circle's plane. But what happens if we change the circle's position? We obtain a surface that has long been known and used in architecture...
Rio Congress:
Algebraic geometry featured in the research of three of the four Fields medalists. Although the French took home no awards, they nevertheless played a prominent role. There was one disappointment, however: St Petersburg was chosen over Paris to host the next ICM, in 2022.
The techniques of the prodigious Terence Tao
Terence Tao is one of the greatest mathematicians of our time. He solves formidable mathematical problems himself. Nor does he hesitate to share his working methods on his widely read blog and offer advice that anyone can put to use.
Reasoning means solving
Reasoning means organizing your thoughts. Yes, but how? Are there methods for keeping our thoughts from descending into anarchy and confusion? Mathematics is, by its very nature, the discipline that has enabled us to answer these questions over the centuries. And it works!
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.
Geometry of footballs: from icosahedron to cube | Tangente
Every World Cup has its own ball. But while the ball's colors and technical features take center stage, let's not forget the mathematics hidden within!