# Four Arithmetic Operations vs Unlock

The clearest difference is in-app purchases: Four Arithmetic Operations at none against Unlock's 1. Four Arithmetic Operations also leads on iOS requirement (7.1 vs 17). On price, ads and device support there is nothing between them.

Both are free to download. Unlock sells 1 one-off in-app purchase. Four Arithmetic Operations asks for nothing beyond the download.

## The numbers

| Metric | Four Arithmetic Operations | Unlock |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | — | Daily |
| Size | 11 MB | 7 MB |
| Requires iOS | **7.1** | 17 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Yu Saito](https://appshunter.io/developer/432081470) | [Pierre Boudoin](https://appshunter.io/developer/970184186) |

## What reviewers say

### Four Arithmetic Operations

[App page](https://appshunter.io/ios/app/four-arithmetic-operations/id1076116230)

**Features:** macOS Compatibility

**In-app purchases:** none


### Unlock

[App page](https://appshunter.io/ios/app/unlock-it-safe-cracker-puzzle/id6738165926)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium Version | $2.99 | one-time |


## Frequently asked questions

### Is Four Arithmetic Operations free?

Four Arithmetic Operations is free to download, with no in-app purchases.

### Is Unlock free?

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

### Do Four Arithmetic Operations or Unlock have ads?

Neither Four Arithmetic Operations nor Unlock shows ads.

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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.*