# Subtraction Math Trainer vs NCA

The clearest difference is price: NCA at Free against Subtraction Math Trainer's $2.99. NCA also leads on update cadence (every 3 months vs every 34 months). Subtraction Math Trainer's advantage is iOS requirement (12.0 vs 15.0). On ads, in-app purchases and device support there is nothing between them.

NCA is free to download; Subtraction Math Trainer costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Subtraction Math Trainer ships an update every 34 months, NCA every 3 months. The most recent releases landed on October 31, 2026 and October 28, 2026 respectively.

## The numbers

| Metric | Subtraction Math Trainer | NCA |
| --- | --- | --- |
| Price | $2.99 | **Free** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 34 months | **Every 3 months** |
| Size | 18 MB | 26 MB |
| Requires iOS | **12.0** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Sergey Malugin](https://appshunter.io/developer/562782409) | [Davy Raitt](https://appshunter.io/developer/1795318281) |

## What reviewers say

### Subtraction Math Trainer

[App page](https://appshunter.io/ios/app/subtraction-math-trainer/id1197851863)

**Features:** macOS Compatibility

**In-app purchases:** none


### NCA

[App page](https://appshunter.io/ios/app/nca-aiio-ai-infrastructure/id6757193320)

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

**In-app purchases:** none


## Frequently asked questions

### Is Subtraction Math Trainer free?

Subtraction Math Trainer costs $2.99, with no in-app purchases.

### Is NCA free?

NCA is free to download, with no in-app purchases.

### Do Subtraction Math Trainer or NCA have ads?

Neither Subtraction Math Trainer nor NCA shows ads.

### Which is updated more often, Subtraction Math Trainer or NCA?

Subtraction Math Trainer ships an update every 34 months, and NCA every 3 months. Most recently, Subtraction Math Trainer was updated on October 31, 2026 and NCA on October 28, 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.*