A day in the life with mathematics
Find out now where mathematics comes into play in Clément and Adina's day.
Today, we're going to follow Clément and Adina, two people with busy schedules, over the weekend to explore how mathematics is present in every moment. From transportation to weather forecasts, leisure activities, shopping, and recipes, mathematics is everywhere, often without us even realizing it.
The goal: by putting yourself in these characters' shoes, you will observe, analyze, and understand how mathematics structures our daily lives. At each stage, you will discover concrete examples illustrating its presence—sometimes in unexpected ways!
Ready to dive into their day? Let's go!
7 am - Unlocking the phone
Clément turns on his phone. Using facial recognition, he unlocks the “standby” mode and checks his notifications. How do you think maths comes into play here?
Find an answer
By activating facial recognition
Facial recognition works using mathematics. It analyzes an image of your face and compares it with other images of you already stored on your phone. To do this, it checks their consistency using calculations and models that identify the distinctive features of your face to verify that it is indeed you.
Find out more: Facial recognition: how does it work? - AFP Animé

8 am – Checking the weather
Adina is awake and drinking her chicory coffee. She checks the weather on her phone to see if she needs to take her umbrella. How do you think maths comes into play here?
Find an answer
By enabling weather forecasting
To forecast the weather, scientists use “partial differential equations” that describe how pressure, temperature, humidity, and wind speed change over time and space. Today, weather forecasts are the result of complex and powerful calculations made possible by computers. These are known as “weather models,” which are fed by satellite data and use probabilities to define different weather scenarios.
Find out more: Weather forecasting models - Météo France

9 am – Commuting
Adina is on her way to an appointment. She realizes she is lost and takes out her phone. How do you think math comes into play here?
Find an answer
Contributing to the functioning of GPS
Before setting off on any journey, it is important to know your exact location. To this end, mathematics powers GPS systems, which are based on several concepts, including Einstein's theory of relativity. Once your location is known, other mathematical theories can be used to calculate different routes.
Find out more: GPS, how does it work? - Lesics français

10 am – Taking the train
Clément jumps on a train to go for a ride in the city. How do you think maths comes into play here?
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By facilitating network management
Mathematics is used in many areas, including rail traffic, to estimate the intervals between two trains on the same track. Statistical models and probabilities can also be used to anticipate and limit delays by analyzing data and predicting their knock-on effects.
Find out more: When maths gets on track - Athena Magazine

11 am - Walking in the rain
Adina forgot her umbrella and doesn't want to get wet (or at least as little as possible!). How do you think maths is useful here?
Find an answer
To know whether to run!
A mathematical model of the human body can estimate the amount of water absorbed, based on running speed, wind, raindrop size, puddles, etc. By the time she has thought about it, Adina is soaked and late.
Find out more: In the rain, should you walk or run to stay drier? - Unisciel

12 pm - Calculating in-store promotions
Clément is doing some shopping. Semolina is advertised with a 30% discount. Opposite the store, the competing brand advertises that if you buy one package, you get the second one at 70% off. In your opinion, how is math useful here?
Find an answer
By allowing him to calculate the best offer and save money
This everyday situation shows how simple percentage calculations can be particularly useful in our daily lives. Mastering basic calculations allows us to save money and sharpen our critical thinking skills when it comes to advertising. Here, if Clement wants to buy two packets of semolina, the second offer is the most advantageous for him.

1 pm – Carrying out renovations
Clément asks his father for advice about making a slab for the future terrace of his house. In your opinion, how is math useful here?
Find an answer
By enabling the calculation of surface areas and quantities of materials
Less surprising, but useful: Clément's father needs mathematics to calculate the surface area of his future terrace, then determine the quantity of materials to purchase.
Find out more: The area of any polygon - MathZkool

2 pm - Illustrating online content
Adina wants to illustrate her website with photos taken a few days earlier. How do you think math comes into play here?
Find an answer
By facilitating image compression
Image compression relies on mathematical tools that reduce file size while limiting the loss of visual quality. For example, the JPEG algorithm begins by dividing the image into 8x8 pixel blocks, then applies a discrete cosine transform (DCT) to convert the spatial information into different frequencies. High frequencies, which are less noticeable to the human eye, are then reduced or removed.
Learn more: JPEG compression - Salem Wizards

3 pm – Improving an application
Clément is preparing his application for an internship and is using artificial intelligence to improve his cover letter. In your opinion, how does math come into play here?
Find an answer
Artificial intelligence is also based on mathematics
Artificial intelligence is widely used for learning, analyzing data, and facilitating decision-making. Mathematics is at the heart of AI, continuously improving its understanding and predictions. Did you know that France offers internationally recognized training in this field?
Find out more: Interview with Arthur Mensch, founder of Mistral IA - Radio France

4 pm – Playing the guitar
Clément is revising his latest piece of music. In your opinion, how does math come into play here?
Find an answer
Mathematics is the basis of musical harmony
Musical harmony is based on precise mathematical relationships between sound frequencies (such as octaves or fifths, minor or major chords, etc.). Rhythm is also structured by mathematical principles, as are certain classical compositions that use symmetrical and balanced forms.
Find out more: Maths & Music: a series of articles combining science and art - Insmi CNRS

5 pm – Solving a sudoku puzzle
Adina starts solving a Sudoku puzzle.
How do you think math comes into play here?
Find an answer
To create the Sudoku grid and solve it using logical deductions
Maths can be fun too! Solving a Sudoku puzzle requires logic. Creating Sudoku grids is also based on mathematics: combinatorics, algorithms, group theory, and programming.
Find out more: The Sudoku Theorem - Automaths - Jason Lapeyronnie

6 pm – Undergoing an MRI scan
Clément accompanies his grandmother to an MRI scan and discovers the cylindrical machine and the results in images. In your opinion, how does math come into play here?
Find an answer
To create an image from data
MRI uses magnetic fields and radio waves to create detailed images of muscles and organs. A mathematical operation called the “Fourier transform” breaks down a signal into its frequency components, thereby converting raw data into images.
Find out more: From Fourier transforms to medical imaging - Interstices.info

7 pm - Watching an animated movie
Adina is releasing the latest animated film by her favorite director. How do you think math comes into play here?
Find an answer
By enabling the creation of digital images
Mathematics makes it possible to create images for animated films by modeling shapes, animating movements, and simulating light. Equations define the curves of a face, calculate trajectories, and ensure smooth, realistic rendering, bringing characters and settings to life.
Find out more: The math behind video games - House of Mathematics and Computer Science

8 pm - Cutting a pizza
Adina shares her pizza with Clément and thinks about the best way to cut it. How do you think maths is useful here?
Find an answer
By allowing the pizza to be divided into equal slices
The “pizza theorem” provides an unbeatable strategy for dividing a pizza into two equal slices, even if its center has not been clearly identified.
Find out more: The pizza theorem - Sylvain Duclos

9 pm - Adapting a recipe
Clément is baking a cake for the next day. The recipe gives proportions for four people, but there will be six people tasting it. In your opinion, how is math useful here?
Find an answer
To calculate the right proportions
Mastering proportionality can be particularly useful, especially to avoid ruining your dish! Following a recipe sometimes requires converting measurements, which is now easier thanks to scales and measuring cups.

10 pm - Playing board games
Clément and Adina are playing a board game and trying to maximize their chances of winning. How do you think math comes into play here?
Find an answer
By enabling them to calculate and anticipate a strategy
Many board games are based on mathematics. The better you are at them, the higher your chances of winning!
Find out more: Nim game - Salem Wizards / The Monty Hall Paradox - Salem Wizards

11 pm - Detecting fraud
Clément and Adina are watching a program in which experts explain how to detect possible fraud. In your opinion, how does math come into play here?
Find an answer
Using Benford's law
Benford's law shows that, in financial data, certain digits appear more often than others in the first position. This rule specifies that in many cases, numbers beginning with 1 appear much more often than those beginning with 9. By comparing this distribution with tax returns, Benford's law makes it possible to identify anomalies and thus potential fraud.
Find out more: Journeys to the Land of Math - Arte TV
