I can't have math. Online mental calculation with a good dose of humor. (Site of teacher)

Last updated on 12 May 2026

I love everything about this teacher's site that allows you to work on mental calculus. It was produced by Benjamin Arsac, who has been teaching Mathematics for about ten years at the Ennemond Richard College in Saint Chamond, Loire. I like everything from its title.

‘I can’t have math’ is a really amazing site that offers online mental calculation sequences for cycles 3 and 4. Nicely done exercises to offer to his students or to do with them in class. It’s light, pretty, effective for training and it’s full of humor. In short, your students will love …

Self-corrected mental calculation exercises in a playful atmosphere

‘I can’t, I have maths’ aims to offer dozens of online mental calculus exercises for grades 1-3. You do not need to register to use it. Everything is simple to understand and the control is immediate. You can advise it without fear to your students.

You just have to choose your level, then the type of operations you want to work on and finally the mode of access for your teacher or student. The progress of each exercise is customizable. We choose the number of calculations proposed for each exercise, the response time granted, the difficulty, etc. One click and go. We're getting into the game fast. Whenever a pupil makes an answer he can check it before moving on to the next calculation.

If you choose the teacher mode, for example, you can project a series of mental calculation operations onto your classroom screen, students write their answers on their notebooks, and it is only after the last puzzle that the right result for all the questions is displayed.

Gamification and humor on the program

How to Incentive Students to training in mental calculus ? Give them a funny interface and the impression of playing rather than learning. Benjamin Arsac perfectly succeeds this recipe in this site of teacher with joyful graphics which offers for example for each level an exercise entitled … »The mental calculation of death!!! ". . . To be faced, of course, only when you have trained in the other exercises at the risk of failing to beat the small vampire-shaped character who challenges you against a background of ‘anguishing’ music.

A great site of mental calculation made available to all young and old by Benjamin Arsac who made all by himself of his little fingers. The project was born during the last lockdowns. Nostalgic for the famous Primath, Benjamin learned to code in CSS/HTML/Javascript for the technical part. A work of several months before arriving at the result that is now online.

I asked him how he used it in his class:

I use the prof mode to work in the form of rituals at the beginning of the session, mental calculation. Students write the results on their notebook as they go and then correct with the correction. We then take stock of the results and make a common correction with explanations.

Development projects for the site? There is no shortage of projects. But it takes energy and time and also a bit of money. A request has been made to the DANE of Lyon to obtain accommodation with database. Waiting for an answer. Hello? the Dane of Lyon…

Benjamin's work deserves recognition and support.

‘I can’t have math’ is completely free and works as well on computer as on tablet or smartphone.

If you are interested in other math teacher sites, take a look at History of mathematics produced by a teacher from Grenoble Alpes University.

If you are looking for a platform for elementary level students, you can also test Matheros, a platform gamified on the same principle of ludo-educational mental calculation.