# SumXMinus – Negative Math

> SumXMinus – Negative Math (iPhone/iPad app by Katsuhiko Yao.)

- Source: https://appshunter.io/ios/app/sumxminus-negative-math/id6480327347 (this page in markdown: same URL + `.md`)
- Developer: [Katsuhiko Yao](https://appshunter.io/developer/1543188534)
- Category: Education, Games
- Price: Free
- Age rating: 4+
- Requires: iOS 16.0 · 32 MB
- Languages: English, Japanese
- Released: 2024-04-08
- Data updated: 2026-07-06
- User reviews in markdown: https://appshunter.io/ios/app/sumxminus-negative-math/id6480327347/reviews.md

## What is SumXMinus?

Created by a Math Teacher

Train your brain in just 30 seconds.

QuickMath Series

A fast and fun way to master mental math.

Can you find the right number pairs?
Use both positive and negative numbers
to reach the target.

Example:
(-2) + (-4) = -6
(-4) + (+5) = 1

Challenge yourself and improve:

• Negative number understanding
• Mental calculation speed
• Focus and thinking skills
From upper elementary to middle school level.

QuickMath Series
• SumX – Number Pair Puzzle
• SumXMinus – Negative Number Training
• Common Divisor – Divisor Brain Training
• Exponent – Power Calculation Challenge
• Decimal Finder – Number Line Intuition


## Version history (last 5 releases)

### 2.1.1 — 2026-06-23

Improved the Result View layout on certain tablet devices, including the iPad Air 11-inch.

* Fixed layout issues on the result screen
* Improved visibility of scores and buttons
* Enhanced overall user experience

### 2.1.0 — 2026-05-11

Improved access to rankings.
You can now quickly open rankings for the current game directly from the top-right button on each game screen.

• Easier access to daily, weekly, monthly, and yearly rankings
• Faster navigation without using the tab bar
• Improved usability and smoother experience
• Minor UI improvements and stability updates

### 0.0.6 — 2026-03-26

リザルト画面の改善を開始しました。
バナー広告の表示を追加し、アプリの安定性も向上しています。

SumXMinusは
数学教師が開発した算数トレーニングアプリです。
今後も授業で使いやすいアップデートを続けていきます。

### 0.0.5 — 2026-02-23

学習に集中できるよう、動作の安定性と操作性を改善しました。
Improved stability and usability to help users stay focused.

### 0.0.4 — 2024-12-10

ランキングの表示方法を変更しました。

## Apps similar to SumXMinus

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [Trig Function(Math Drills)](https://appshunter.io/ios/app/trig-functionmath-drills/id1670535500) | 5.0 (1) | Free | Education |
| [Anzan19x19](https://appshunter.io/ios/app/anzan19x19/id1495063370) | — | Free | Education |
| [九九 掛け算の達人 ! - かけざん（九九）小学2年生](https://appshunter.io/ios/app/2/id1628035452) | 4.8 (6) | Free | Education |
| [MaxwellsDemon](https://appshunter.io/ios/app/maxwellsdemon/id1612817641) | — | $0.99 | Education |
| [Famous Paintings Quiz](https://appshunter.io/ios/app/famous-paintings-quiz/id1491818320) | 3.6 (7) | Free | Education |
| [Probability(Math Drills)](https://appshunter.io/ios/app/probabilitymath-drills/id1632889899) | — | Free | Education |

## More apps by Katsuhiko Yao

- [QuickAge](https://appshunter.io/ios/app/quickage/id1545922757)
- [QuickCheck3](https://appshunter.io/ios/app/quickcheck3/id1566831890)
- [AddToMinusX](https://appshunter.io/ios/app/addtominusx/id6443640661)
- [Multiply Pairs – Mental Math](https://appshunter.io/ios/app/multiply-pairs-mental-math/id6448858474)
- [Power of 2](https://appshunter.io/ios/app/power-of-2/id6450391335)
- [Neg Multiply – Brain Training](https://appshunter.io/ios/app/neg-multiply-brain-training/id6450744705)

All apps by Katsuhiko Yao: https://appshunter.io/developer/1543188534

## Related topics

[negative numbers](https://appshunter.io/ios/topics/negative-numbers)

---

*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-07-06.*