This Open Source Android App Fights Brainrot With Basic Math Problems

Mental Math tests your arithmetic skills without tracking your every move.
Warp Terminal

Short-form content has ruined attention spans for many people, including myself. Those little dopamine hits feel good in the moment. But over time, they make you impulsive, easily irritated, and exhausted.

Let it control you long enough, and it becomes like any other addiction. Your brain gets used to constant stimulation. Normal activities feel boring. You need more just to feel okay.

Your ability to focus on anything substantial crumbles. Work becomes harder. Relationships suffer, and if you are on the spectrum, then all of this hits even harder.

But there are many ways out. One of them is Mental Math, an app that tests your arithmetic skills while keeping you productively engaged. No endless scrolling, no algorithm deciding what you consume, and no brainrot.

Just math problems that actually make you think.

Mental Math: Keep the Brainrot Away

Mental Math is a free and open source arithmetic training app developed by Alexander Goy (HeldDerTierwelt). The app is written in Kotlin and respects your privacy. It collects no data, requires no permissions, displays no ads, and works completely offline.

Key features include:

  • Customizable tests (addition, subtraction, multiplication, division) with 9 difficulty levels.
  • Two game modes: Task Mode to complete 10-50 problems and Timed Mode to tackle problems in 1-5 minutes.
  • You can share games with friends using identical problems or preset configurations to challenge them.
  • Difficulty calculation happens using algorithms based on column addition, column subtraction, long multiplication, and long division.

For testing Mental Math, I loaded this up on an Android smartphone to see how it worked. The home page immediately lets you select which arithmetic operations to practice and at what difficulty level.

I set middle ground difficulty for all operations and tried tests with 10 and 30 problems, and Task Mode seemed like the right place to start.

this four-part image, from left to right, shows the addition, substraction, multiplication, and division arithmetic tests on mental math
The arithmetic tests are quite diverse!

My arithmetic skills need work. But the interface makes going through tests easy. You see the problem above; you type the solution using the number keypad below.

Correct answers flash green before the next question appears. Wrong answers show red. Simple feedback that keeps you moving.

When a test ends, you get a results page with useful metrics like accuracy, speed, and score. The developer encourages sharing these with friends to compare performance on identical tasks.

this two-part image shows the results page of a arithmetic test done in the mental math app, there are some interesting metrics showing how I performed (miserably)
My expertise in arithmetic is rivaled by many.

The app has more than just arithmetic skill testing. A sidebar menu gives access to settings and additional features. Tap the bar graph icon on the top right to see your top 10 scores for each difficulty combination.

There is also a history page where you can browse all your past games and sort them by time or score.

Install Mental Math

This app is only available for Android users. You can get it from F-Droid, the Play Store, or directly from the releases page of the project's repository on Codeberg, where the source code is also available.

💬 What is your approach to escaping mindless scrolling? Let me know in the comments below!

About the author
Sourav Rudra

Sourav Rudra

A nerd with a passion for open source software, custom PC builds, motorsports, and exploring the endless possibilities of this world.

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