# Serial 7 — Serial Sevens Subtraction.

> A game for rapid serial subtraction of seven to test and improve cognitive skills. (iPhone/iPad app by HFX Lab.)

- Source: https://appshunter.io/ios/app/serial-7/id6480178276 (this page in markdown: same URL + `.md`)
- Developer: [HFX Lab](https://appshunter.io/developer/1139262927)
- Category: Games, Education, Trivia
- Price: Free
- Rating: 5.00/5 from 1 App Store ratings
- Age rating: 9+
- Requires: iOS 12.0 · 34 MB
- Languages: American English, Korean
- Released: 2024-04-01
- Data updated: 2026-08-24
- Monetization: ad-supported
- User reviews in markdown: https://appshunter.io/ios/app/serial-7/id6480178276/reviews.md

## What is Serial 7?

Serial 7 is a game that tests how quickly you can subtract 7 in a row from a given number.

It is a slight variation of the serial 7 subtraction test, which is one of the items on the MMSE(Mini-Mental State Examination).
A starting number between 94 and 100 is randomly selected, and you measure the time it takes until you can't subtract any more 7.

The subtraction of consecutive sevens task is used to test attention and memory, and consistent testing can help improve brain skills such as attention and memory.
It can also help prevent cognitive decline that occurs with everyday activities and reduce the likelihood of developing dementia.
They can also be used to see how an individual's cognition changes over time.

Recommended for users interested in brain health and training, and dementia prevention.

## Key features

- Serial 7 subtraction gameplay
- Tests attention and memory
- Helps prevent cognitive decline
- Measures subtraction speed
- Randomized starting numbers


## Frequently asked questions about Serial 7

### What is Serial 7?

Serial 7 is a game designed to test and improve your ability to subtract the number seven consecutively from a starting number. It's based on a cognitive test used to assess attention and memory.

### How does Serial 7 help with brain health?

Consistent play of Serial 7 can help improve brain skills such as attention and memory. It is also recommended for users interested in dementia prevention and maintaining cognitive function.

### What is the gameplay like in Serial 7?

The game randomly selects a starting number between 94 and 100. You then measure how quickly you can subtract 7 in a row until you can no longer continue the sequence.

### Is Serial 7 free to play?

Yes, Serial 7 is free to download and play. However, it does contain advertisements.

### Does Serial 7 have ads?

Yes, Serial 7 contains advertisements.

### What devices is Serial 7 available on?

Serial 7 is available on iPhone, iPad, and iPod devices.

### What is the age rating for Serial 7?

Serial 7 has an age rating of 9+.

### How often is Serial 7 updated?

The latest version of Serial 7 is 1.0.3, and it was last updated on August 20, 2024.

## Version history (last 3 releases)

### 1.0.3 — 2024-08-20

Improved the performance.

### 1.0.1 — 2024-04-05

- Added a daily notification feature.

### 1.0.0 — 2024-04-01

No release notes.

## Apps similar to Serial 7

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [aLemon](https://appshunter.io/ios/app/alemon/id6479625346) | 5.0 (1) | Free | Games |
| [Guess Chess - Guess the Move!](https://appshunter.io/ios/app/guess-chess-guess-the-move/id6753637134) | 5.0 (2) | Free | Games |
| [97 – Prime Number Puzzle](https://appshunter.io/ios/app/97-prime-number-puzzle/id6475675534) | — | Free | Games |
| [PrimeXTime](https://appshunter.io/ios/app/primextime/id1253706544) | 5.0 (2) | Free | Games |
| [초성퀴즈!](https://appshunter.io/ios/app/id6749453667) | — | Free | Games |
| [Find Number!](https://appshunter.io/ios/app/find-number/id6476119232) | — | Free | Games |

## More apps by HFX Lab

- [Surveying Leveling Field Notes](https://appshunter.io/ios/app/surveying-leveling-field-notes/id1462164977)
- [스마트스토어 쇼핑몰 키워드 순위](https://appshunter.io/ios/app/id1475385541)
- [모두의 띠별운세](https://appshunter.io/ios/app/id1483205926)
- [모두의 별자리운세](https://appshunter.io/ios/app/id1483310997)
- [폰티](https://appshunter.io/ios/app/id1518746370)
- [ProfilePlate - Text Profile](https://appshunter.io/ios/app/profileplate-text-profile/id1559961538)

All apps by HFX Lab: https://appshunter.io/developer/1139262927

## Related topics

[hfx lab](https://appshunter.io/ios/topics/hfx-lab)

---

*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 2026-08-24.*