# Add and subtract within 20 vs Rechentrainer

The clearest difference is review sentiment: Rechentrainer at 100% against Add and subtract within 20's 33%. Rechentrainer also leads on price (Free vs $2.99) and update cadence (every 2 months vs every 36 months). Add and subtract within 20's advantage is iOS requirement (12.0 vs 14.2). On ads, in-app purchases and device support there is nothing between them.

Rechentrainer is free to download; Add and subtract within 20 costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Add and subtract within 20 ships an update every 36 months, Rechentrainer every 2 months. Both last shipped on November 3, 2026.

## The numbers

| Metric | Add and subtract within 20 | Rechentrainer |
| --- | --- | --- |
| Price | $2.99 | **Free** |
| Positive reviews | 33.3% of reviews | **100.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 36 months | **Every 2 months** |
| Monetization | Paid | **Free** |
| Size | 18 MB | 7 MB |
| Requires iOS | **12.0** | 14.2 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Sergey Malugin](https://appshunter.io/developer/562782409) | [Nicolai Kummer](https://appshunter.io/developer/1497635656) |

## What reviewers say

### Add and subtract within 20

[App page](https://appshunter.io/ios/app/add-and-subtract-within-20/id757149544)

This app transforms math practice into an exciting adventure for children. It uses interactive mini-games and handwriting recognition to make learning addition and subtraction within 20 fun and effective. The difficulty adapts to your child's progress for a personalized experience.

**Highlights:** Interactive mini-games, Handwriting recognition, Adaptive difficulty, Targeted addition/subtraction practice, Natural learning input

**Features:** macOS Compatibility

**In-app purchases:** none


### Rechentrainer

[App page](https://appshunter.io/ios/app/rechentrainer/id1497635657)

This app offers personalized math practice for all ages, covering addition, subtraction, multiplication, and division. It features customizable difficulty levels, motivational rewards, and progress tracking to make learning enjoyable and effective.

**Highlights:** Personalized arithmetic practice, Customizable difficulty levels, Motivational reward system, Learning progress tracking, Suitable for all ages

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Add and subtract within 20 free?

Add and subtract within 20 costs $2.99, with no in-app purchases.

### Is Rechentrainer free?

Rechentrainer is free to download, with no in-app purchases.

### Do Add and subtract within 20 or Rechentrainer have ads?

Neither Add and subtract within 20 nor Rechentrainer shows ads.

### Which is updated more often, Add and subtract within 20 or Rechentrainer?

Add and subtract within 20 ships an update every 36 months, and Rechentrainer every 2 months. Most recently, Add and subtract within 20 was updated on November 3, 2026 and Rechentrainer on November 3, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*