# Know Abacus vs Flash Mental Math

The clearest difference is in-app purchases: Flash Mental Math at none against Know Abacus's 1. Know Abacus's advantage is ratings volume (67 vs 18) and iOS requirement (11.0 vs 15.6). On price, rating, update cadence and ads there is nothing between them.

Both are free to download. Know Abacus sells 1 one-off in-app purchase. Flash Mental Math asks for nothing beyond the download.

On the App Store both sit at effectively the same score — 4.7 for Know Abacus against 4.7 for Flash Mental Math. Both are backed by a comparable volume of ratings — 67 and 18 respectively.

Know Abacus ships an update every 2 months, Flash Mental Math every 3 months. The most recent releases landed on October 15, 2026 and September 29, 2026 respectively.

## The numbers

| Metric | Know Abacus | Flash Mental Math |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.7 (67 ratings)](https://appshunter.io/ios/app/know-abacus/id641867438/reviews) | [4.7 (18 ratings)](https://appshunter.io/ios/app/flash-mental-math-simple/id1547944841/reviews) |
| Number of ratings | **67** | 18 |
| Positive reviews | 96.4% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | Yes | Yes |
| Update frequency | **Every 2 months** | Every 3 months |
| Monetization | Free with in-app purchases | **Ad-supported** |
| Size | 28 MB | 14 MB |
| Requires iOS | **11.0** | 15.6 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Kittipong Mungnirun](https://appshunter.io/developer/488058533) | [Ryouhei Azuma](https://appshunter.io/developer/1353297781) |

## What reviewers say

### Know Abacus

[App page](https://appshunter.io/ios/app/know-abacus/id641867438)

This app teaches children how to use an abacus for various math operations. It covers counting, addition, subtraction, multiplication, and division, helping to develop their mathematical abilities and brain potential. It offers multiple learning modes and customization options.

**Highlights:** Abacus counting, Addition and subtraction (1 & 2 digits), Multiplication and division (1-2 digits), Mental math practice, Review and random lessons, Customizable abacus (color, touch), Multiple languages

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Remove Ads | $2.99 | one-time |


### Flash Mental Math

[App page](https://appshunter.io/ios/app/flash-mental-math-simple/id1547944841)

Practice mental arithmetic with various difficulty levels and custom modes. This app serves as a brain training tool to enhance calculation skills.

**Highlights:** Mental arithmetic practice, Easy, normal, and difficult modes, Customizable modes, Brain training, Calculation skill improvement

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Know Abacus free?

Know Abacus is free to download, with in-app purchases available.

### Is Flash Mental Math free?

Flash Mental Math is free to download, with no in-app purchases.

### Which has better reviews, Know Abacus or Flash Mental Math?

Know Abacus and Flash Mental Math are both rated 4.7 out of 5 on the App Store, from 67 and 18 ratings respectively.

### Do Know Abacus or Flash Mental Math have ads?

Both Know Abacus and Flash Mental Math show ads.

### Which is updated more often, Know Abacus or Flash Mental Math?

Know Abacus ships an update every 2 months, and Flash Mental Math every 3 months. Most recently, Know Abacus was updated on October 15, 2026 and Flash Mental Math on September 29, 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.*