Practice mental arithmetic solo or compete with friends.
About this app
"Mental Math" is a simple and clean Android app for mental arithmetic training. You can practice on your own or challenge friends to compete and improve your skills. The app is open source and respects your privacy.
Customizable Training Select which arithmetic operations to include (+, −, ×, ÷). For each operation, choose from nine difficulty levels to customize your training precisely to your skill level.
Two Game Modes • Practice Mode lets you complete a fixed number of problems (10, 20, 30, 40, or 50). • Timed Mode challenges you to solve as many problems as possible within a time limit (1, 2, 3, 4, or 5 minutes).
Challenge your Friends You can share a game link to: 1. Replay a completed game with the exact same problems to compare scores with friends. 2. Start a new game with preset settings for a fair and fresh challenge for everyone.
Difficulty Calculation Problem difficulty is determined using algorithms based on column addition, column subtraction, long multiplication, and long division, creating realistic and well-balanced exercises.
Detailed Results After each game, view a detailed summary that includes your selected settings, your performance (accuracy, speed, and score), and a complete list of all your problems and answers for review.
Personal Leaderboard Your top 10 results are displayed separately for each combination of settings, allowing you to easily track your progress. You can also review detailed summaries of your top games at any time.
Game History Explore the complete history of all your scored games. You can sort the list by time or numerically to find specific games. Anytime, you can revisit any match to view a detailed summary of its results.
Practice Reminders Set up periodic reminders to support regular mental math practice. Notifications are sent in the evening (around 6 p.m.) and can be scheduled daily, every three days, or weekly.
Clean Design A simple and minimalist app design with no unnecessary elements or distractions, designed to keep your focus fully on mental math training. Supports both light and dark modes.
Open Source, Private, Free & Ad-free "Mental Math" is fully open source, free to use, and does not contain any ads. It also does not collect, store, or process any personal data, nor does it use trackers or third-party services.
Licensed under GPL-3.0-only, by HeldDerTierwelt.
What's New in v25
Imported from the F-Droid repository index.
- - Added Italian translation contributed by zini.simons. Thank you! :)
- - Added Greek translation contributed by Nick Batzakis. Thank you! :)
- - Added German translation.
- - fixed bug for devices with older version of SQLite
- - Enable per-app language selection via Android system settings (requires Android 13 or higher)
- - Prepared for sound effects for correct and incorrect answers in the future.
Version history
Jun 18, 2026 · 11.7 MB · Android API 24–36 · code 25
Imported from the F-Droid repository index.
- - Added Italian translation contributed by zini.simons. Thank you! :)
- - Added Greek translation contributed by Nick Batzakis. Thank you! :)
- - Added German translation.
- - fixed bug for devices with older version of SQLite
- - Enable per-app language selection via Android system settings (requires Android 13 or higher)
- - Prepared for sound effects for correct and incorrect answers in the future.
SHA-256 497c7c2b33316fca60a09d8091b9af71ff455508e88a65530a2ca8799df92c7e
May 4, 2026 · 11.5 MB · Android API 24–36 · code 24
Imported from the F-Droid repository index.
- - Added French translation contributed by @mdk. Thank you! :)
- - Removed “Total Score” and renamed “Active Score” to simply “Score” to reduce confusion
- - Added tooltips to the game overview for improved clarity
- - Reworked the speed statistic: now displayed as time per correct answer instead of correct answers per minute
- - Fixed a crash when using the “About” or “Feedback” options on systems without a default browser or mail client
- - Added a message to the problem overview when no problems have be
SHA-256 1aeae599ceb630a3a7ad6846787a192f64e47bd935e755038fdcfee48e4d93f3
Apr 10, 2026 · 11.2 MB · Android API 24–36 · code 23
Imported from the F-Droid repository index.
- - Input field is now clickable to switch input direction while in game
- - Also added a popup notification when switching input direction in game
- - Improved a few colors
- - Dependency updates
SHA-256 a4a702fbcb81d5e538a228e6d067698552fddb98cd2950c78e9bebd7f4433f7e
Will it run on your device?
92%
- Runs on a broad range of modern Android versions.
- Multiple CPU architectures are covered.
- Aligned with the latest Android target SDK expectations.
Installation Guide
Open Settings on your Android device
Go to Security → Unknown sources (or Install unknown apps)
Enable "Allow from this source" for your browser or file manager
Open the downloaded APK file from your Downloads folder
Tap "Install" and wait for installation to complete
Launch the app from your home screen
Make sure to re-enable Unknown Sources restrictions after installation for security.
How to install this safely
How to verify the file you downloaded
Before you install anything, confirm the file is the one described here. On a computer, run shasum -a 256 your-download.apk (macOS or Linux) or certutil -hashfile your-download.apk SHA256 (Windows), then compare the output character-for-character with the SHA-256 on this page. If a single character differs, the file is not the build we recorded — delete it.
What the signing certificate proves
Every Android app is signed with a private key that only its developer holds. The fingerprint on this page is a hash of the matching public certificate, and it proves continuity rather than identity: it tells you a build came from whoever signed the earlier ones. Android enforces this at install time — if a package claiming to be com.helddertierwelt.mentalmath is signed with a different key, the system will refuse to install it over your existing copy. A fingerprint that changes between releases is worth pausing on, because a repackaged app that has been modified by someone else cannot keep the original signature.
How to roll back to an earlier version
If the current release misbehaves, 24 is the last build before it. Android will not install an older version code over a newer one, so you must uninstall Mental Math first — which clears its local data unless you have a backup. Reinstall the older APK only if its signing fingerprint matches the build you already trust, and check the API range: an older release may target an Android version your device has moved past.
Why we list sources instead of hosting everything
The official store channel is almost always the right choice: it updates automatically and carries the publisher's own distribution guarantees. A direct APK is useful when a device has no store access, when a rollout has not reached your region, or when you need a specific version — and only when the publisher has authorized that copy. APKBrowse does not list pirated, cracked, or unauthorized rebuilds of Mental Math, and a listing is removed when the evidence for it stops holding up.
Get Mental Math
Every source we list for com.helddertierwelt.mentalmath is legality-reviewed. Pirated or cracked builds are never offered.
Other sources
F-Droid listing
officialF-Droid builds this app from source and signs it. This is its official listing, with older builds and full release notes.
Source code
verified publisherThe upstream repository this build is compiled from.
We check legality and signature continuity, but device behaviour still varies. Install at your own discretion.
App Information
Security Verification
We record provenance; we do not run malware scans. Verify the hash yourself before installing.
SHA-256 Hash
497c7c2b33316fca60a09d8091b9af71ff455508e88a65530a2ca8799df92c7e
Signing certificate
de197b4cf2b85880e0211159b60b6e3c39f96ff06868ae4839c42d8a4d6f3fe5
Permissions Required
Previous Versions
The signing certificate fingerprint for this release is on record, so a build that does not match it did not come from this publisher.
Report a problem with this listing
A listing is only as good as its corrections. If a source is broken, a signature looks wrong, or this app should not be here, tell the moderation team.