# Protractor Teacher vs f(x) Calc

The clearest difference is price: f(x) Calc at Free against Protractor Teacher's $0.99. f(x) Calc also leads on rating (5.0 vs 4.5) and update cadence (every 10 days vs every 42 months). Protractor Teacher's advantage is in-app purchases (none vs 1) and iOS requirement (13.0 vs 16.6). On ratings volume, ads and device support there is nothing between them.

f(x) Calc is free to download; Protractor Teacher costs $0.99 up front. f(x) Calc sells 1 one-off in-app purchase. Protractor Teacher asks for nothing beyond the download.

f(x) Calc holds the better App Store score, 5.0 against 4.5. Both are backed by a comparable volume of ratings — 2 and 1 respectively.

Protractor Teacher ships an update every 42 months, f(x) Calc every 10 days. The most recent releases landed on October 22, 2026 and October 10, 2026 respectively.

## The numbers

| Metric | Protractor Teacher | f(x) Calc |
| --- | --- | --- |
| Price | $0.99 | **Free** |
| Rating | [4.5 (2 ratings)](https://appshunter.io/ios/app/protractor-teacher/id1526985063/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/fx-calc/id6760609257/reviews)** |
| Number of ratings | **2** | 1 |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 42 months | **Every 10 days** |
| Monetization | Paid | **Free** |
| Size | 1 MB | 5 MB |
| Requires iOS | **13.0** | 16.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Alistair Shaw](https://appshunter.io/developer/959356999) | [David Russell](https://appshunter.io/developer/1104864276) |

## What reviewers say

### Protractor Teacher

[App page](https://appshunter.io/ios/app/protractor-teacher/id1526985063)

This geometry app overlays a virtual protractor onto images. Users can rotate and move the protractor to learn how to accurately measure angles in various contexts.

**Highlights:** Virtual protractor overlay, Image angle measurement, Protractor rotation, Protractor repositioning, Geometry education tool

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

**In-app purchases:** none


### f(x) Calc

[App page](https://appshunter.io/ios/app/fx-calc/id6760609257)

A full-featured scientific calculator designed for math and science students. It offers natural math entry and includes built-in examples to aid learning. A simplified Junior mode is available for everyday use.

**Highlights:** Natural Maths entry, Built-in learning examples, Junior mode for everyday use, Ideal for math and science study, Full-featured scientific calculator

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Full Access | Free | one-time |


## Frequently asked questions

### Is Protractor Teacher free?

Protractor Teacher costs $0.99, with no in-app purchases.

### Is f(x) Calc free?

f(x) Calc is free to download, with in-app purchases available.

### Which has better reviews, Protractor Teacher or f(x) Calc?

f(x) Calc is rated higher. Protractor Teacher averages 4.5 out of 5 from 2 ratings, while f(x) Calc averages 5.0 from 1 ratings.

### Do Protractor Teacher or f(x) Calc have ads?

Neither Protractor Teacher nor f(x) Calc shows ads.

### Which is updated more often, Protractor Teacher or f(x) Calc?

Protractor Teacher ships an update every 42 months, and f(x) Calc every 10 days. Most recently, Protractor Teacher was updated on October 22, 2026 and f(x) Calc on October 10, 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.*