# Mental Math for Work vs 脳内そろばん

The clearest difference is update cadence: Mental Math for Work at every 9 days against 脳内そろばん's monthly. On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Mental Math for Work sells 2 in-app purchases, starting at $1.99 per month and 脳内そろばん sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

Mental Math for Work ships an update every 9 days, 脳内そろばん monthly. The most recent releases landed on October 14, 2026 and October 23, 2026 respectively.

## The numbers

| Metric | Mental Math for Work | 脳内そろばん |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Every 9 days** | Monthly |
| Size | 15 MB | 5 MB |
| Requires iOS | 18.0 | **17.0** |
| Devices | **iPhone, iPad** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Shota Morioka](https://appshunter.io/developer/483674380) | [Ryo Sato](https://appshunter.io/developer/1831657696) |

## What reviewers say

### Mental Math for Work

[App page](https://appshunter.io/ios/app/mental-math-for-work/id6766879948)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium Monthly | $1.99 | per month |
| Premium Lifetime | $9.99 | one-time |


### 脳内そろばん

[App page](https://appshunter.io/ios/app/id6790279857)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| プレミアム | $3.99 | one-time |


## Frequently asked questions

### Is Mental Math for Work free?

Mental Math for Work is free to download, with in-app purchases available.

### Is 脳内そろばん free?

脳内そろばん is free to download, with in-app purchases available.

### Do Mental Math for Work or 脳内そろばん have ads?

Neither Mental Math for Work nor 脳内そろばん shows ads.

### Which is updated more often, Mental Math for Work or 脳内そろばん?

Mental Math for Work ships an update every 9 days, and 脳内そろばん monthly. Most recently, Mental Math for Work was updated on October 14, 2026 and 脳内そろばん on October 23, 2026.

---

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