Like Émilie, many adults regret not having been more diligent during their math lessons. Especially with regard to this very useful operation in everyday life.
Some mathematics courses are sometimes so precise that we tend to wonder how it would be useful to us later, unless we are moving towards scientific careers. Geometry, for example, is essential for anyone who wants to become an architect, statistics are useful for establishing market studies, but not only that. This scientific subject, and certain calculations in particular, must be mastered from a very young age, because they are essential in everyday life. “When I was young, I didn’t see how vectors and fractions would help me in the future, especially since I chose a more literary major. But today, I regret not having been more diligent in class, because mathematics is useful to us every day.” tells us Emilie, aged 32.
Today, with new technologies, calculators, as well as the apps integrated into our smartphones, save the day a little when we are hesitant about the numbers. “Without my calculator, I feel like I can’t count at all.” regrets Emilie, who has adopted bad habits, having the reflex to use new technologies. Indeed, certain operations such as mental arithmetic, multiplication tables to be known by heart, and percentages should be known to everyone as they are useful every day: for doing our shopping, calculating a price on promotion in stores, for converting a sum in a foreign currency or convert a liquid when you want to cook… Knowing how to calculate a percentage also helps us to understand our employer when he speaks to us in gross or net income, but also our banker who helps us determine the amount of the interest rates…
According to Yvan Monka, associate professor of mathematics and author of the YouTube channel “m@ths et ticks” interviewed by Le Figaro Etudiant, the cross product is another calculation, “taught from the 4th grade, but which the students do not master still not in high school,” he explains. However, it is “the most useful to know for solving problems of daily life proportions and the simplest to master”.
For example, it allows you to know the price of the trip in the following situation: “Amine is used to carpooling while always using the same application. He remembers having paid 4.20 euros for 70 kilometers. For his next trip, Amine will have to travel 358 kilometers. How much should this journey cost him? To calculate the cost of this journey, you will therefore have to use the following calculation: 358 x 4.20 / 70 = 21.48 euros.