# Quick mental calculation vs Calculator Challenge

The clearest difference is in-app purchases: Quick mental calculation at none against Calculator Challenge's 1. On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Calculator Challenge sells 1 one-off in-app purchase. Quick mental calculation asks for nothing beyond the download.

## The numbers

| Metric | Quick mental calculation | Calculator Challenge |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | Yes | Yes |
| Update frequency | Every 11 days | — |
| Size | 21 MB | 98 MB |
| Requires iOS | 12.0 | **11.0** |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [ERX](https://appshunter.io/developer/513941286) | [Maysalward UK](https://appshunter.io/developer/1241753360) |

## What reviewers say

### Quick mental calculation

[App page](https://appshunter.io/ios/app/quick-mental-calculation/id841970890)

**Features:** macOS Compatibility

**In-app purchases:** none


### Calculator Challenge

[App page](https://appshunter.io/ios/app/calculator-challenge/id1611345246)

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Remove Ads | $3.99 | one-time |


## Frequently asked questions

### Is Quick mental calculation free?

Quick mental calculation is free to download, with no in-app purchases.

### Is Calculator Challenge free?

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

### Do Quick mental calculation or Calculator Challenge have ads?

Both Quick mental calculation and Calculator Challenge show 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.*