# Calcul Mental Challenge

> Free educational mental math app for students from 1st grade to high school (ages 6-18). Created by Laurent BOST, a French school IT worker and father of two.

## What is it

Calcul Mental Challenge is a completely free, ad-free, no-subscription educational math game. It is available on Windows, Mac, Linux, Android, and iOS. It is used by teachers in French schools for classroom math sessions and by students at home for practice.

## Key facts (v0.4.5, April 2026)

- 100% free, no ads, no in-app purchases, no subscription, no tracking
- 13 operation types: addition, subtraction, multiplication, division, fractions, decimals, powers, cascades, complements, doubles/halves, estimation, missing numbers, equations
- 12 game modes: Classic, Table Training, Problems, Story Mode, Crossword Math, Logical Sequences, Equations, Chain Calculation, Time Attack, Survival (reverse timer), Ascension (climb school levels), Friend Challenge, Long Division, Tower of Calculation
- Online modes: 1v1 Duels (ELO ranking, level-filtered ±1 grade), Battle Royale (level-filtered), Weekly Leagues (Bronze to Diamond), Coop vs Boss (5 historical bosses: Dragon, Sophie Germain, Ada Lovelace, Newton, Einstein), School Wars, Class Battles, Class bracket Tournaments, Permanent rooms (level-filtered, open 24/7)
- Teacher mode: create classroom sessions via school WiFi (LAN), track student progress, generate PDF reports, period-based evaluation (P1-P5 aligned with French curriculum), targeted homework (per-student differentiation), bracket tournaments, "ready to advance" indicator
- Family mode: 1-2 parents share a household with up to 6 children, give targeted per-child homework, track progress, help recover lost recovery codes. Family data is visible only to family members, never publicly.
- 12 school levels: CE1, CE2, CM1, CM2, 6eme, 5eme, 4eme, 3eme, 2nde, 1ere, Terminale, Concours
- 60+ badges, 220 collectible Mathemonsters cards (NEW v0.4.5, with friend trade by 6-7 character code or QR scan), 60 avatars, downloadable music library auto-classified by age (primary/middle/high school)
- The 220-card collection includes a great saga of women mathematicians: Hypatia of Alexandria, Maria Gaetana Agnesi, Émilie du Châtelet, Sophie Germain, Nicole-Reine Lepaute, Mary Somerville, Sofia Kovalevskaïa, Ada Lovelace, Emmy Noether, Maryam Mirzakhani (10 cards each, 100 cards total)
- BGM auto-adapts to student grade: nursery rhymes for primary, lo-fi/electro for middle school, ambient/piano for high school. Toggle "full library" available in audio settings.
- GDPR compliant, data stored locally, no email required, parental consent for online mode under 15 (article 8 GDPR), no profiling, no automated decisions (article 22 GDPR)
- Available in 4 languages: French, English, Spanish, Chinese (all 3 tutorials translated: student, teacher, parent)
- Hosted in Europe (IONOS Germany), Content Security Policy strict, IP rate limiting (1000 req/min auto-ban), recovery codes hashed (HMAC-SHA256)

## Who should use it

- Students (ages 6-18) who want to practice mental math in a fun, game-like environment
- Teachers who need a free, ad-free tool for classroom math sessions with real-time tracking
- Parents looking for a safe, free educational app without ads or hidden costs
- Schools deploying via Microsoft Intune (silent install + auto-update agent)

## Platforms

- Windows: installer (.exe) with auto-update via scheduled task
- macOS: .dmg with auto-update
- Linux: AppImage and .deb
- Android: APK (direct download) and AAB (Google Play, closed beta)
- iOS: App Store (https://apps.apple.com/app/calcul-mental-challenge/id6761807166)

## Links

- Website: https://studiophel.fr
- Download: https://studiophel.fr/#telechargement
- Tutorials hub (FR): https://studiophel.fr/tutoriels.html
- Tutorials hub (EN): https://studiophel.fr/en/tutorials.html
- Student tutorial: https://studiophel.fr/tuto-eleve.html (FR), https://studiophel.fr/en/student-tutorial.html (EN)
- Teacher tutorial: https://studiophel.fr/tuto-enseignant.html (FR), https://studiophel.fr/en/teacher-tutorial.html (EN)
- Parent tutorial: https://studiophel.fr/tuto-parent.html (FR), https://studiophel.fr/en/parent-tutorial.html (EN)
- Privacy policy: https://studiophel.fr/confidentialite.html
- FAQ: https://studiophel.fr/faq.html
- Contact: contact@studiophel.fr

## Press

- TICE-Education (2026): "Calcul Mental Challenge : l'application gratuite qui revolutionne les maths du CE1 au lycee" - https://www.tice-education.fr/tous-les-articles-er-ressources/tablettes-numeriques/1914-calcul-mental-challenge-lapplication-gratuite-qui-revolutionne-les-maths-du-ce1-au-lycee

## Comparison with alternatives

Unlike Duolingo Math (discontinued), Khan Academy (video-focused), or Kahoot (requires teacher-created quizzes), Calcul Mental Challenge:
- Is 100% free with no premium tier
- Works offline and on local network (no internet needed for classroom use)
- Covers the full French curriculum from CE1 to Terminale
- Includes competitive modes (duels, leagues, school wars) that motivate students
- Has a built-in teacher dashboard with no account creation needed
- Stores data locally first (privacy by design)