calcMod vs Pythagoras Interactive
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
calcMod
This application helps users perform complex mathematical calculations, including factorials, primality tests, and modular arithmetic. It's designed for students and educators interested in number theory and the properties of integers.
- Factorial calculation up to 80!
- Primality testing with change mod function
- Divisor identification
- Modular exponentiation
- Modular inverse calculation
- Number storage and recall
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What are all the digits of the factorial of 79 and how many digits ? Want to know if a big integer is prime ? The change mod function indicates when the number is prime. Want to know the divisors of an integer ? A prime divisor has no inverse modulo this integer. The "n!" button calculates the factorial of an integer from 0 to 80. Factorial are limited to factorial of 80, but the calculator could calculate them up to 2000 ! (ProX version) The "change mod" (change modulo) function indicates when the modulo is prime. There is a limit to 10^10 for modulo in this FREE version (no limit with ProX version). You can stoke one number and recall it when you want. The "Mod" operation indicates the residue modulo N. The exp function allow modular exponentiation (as + - *) The "INV" function calculates the inverse of an integer modulo N. This app is intended for both mathematics teachers and/or their students, or if you are interested in the beauty of numbers. Enjoy calcMod-Light ! Les commentaires sont disponibles en français (réglages).
Pythagoras Interactive
Explore the Pythagorean Theorem with an interactive visual tool. Adjust triangle legs to observe real-time changes in square areas and hypotenuse length. Distances are displayed in radical form when necessary.
- Interactive triangle manipulation
- Visual representation of squares on sides
- Real-time updates to hypotenuse and areas
- Radical form for distances
- Clear labeling of sides and areas
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Eureka! An interactive illustration of the Pythagorean Theorem. Drag the legs of the right triangle and watch the three squares transform in real time. Every side shows its length, every square its area — in radical form when needed, so you'll see 2√2 rather than 2.828. Slide through a visual demonstration of Euclid's original proof from Book I of the Elements. Understand why the theorem is always true, not just what it claims.
Screenshots
Verdict
The clearest difference is update cadence: Pythagoras Interactive at every 2 weeks against calcMod's every 18 months. On price, rating, ratings volume and ads there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
On the App Store both sit at effectively the same score — 5.0 for calcMod against 5.0 for Pythagoras Interactive. Both are backed by a comparable volume of ratings — 1 and 1 respectively.
calcMod ships an update every 18 months, Pythagoras Interactive every 2 weeks. The most recent releases landed on October 19, 2026 and October 16, 2026 respectively.
| Parameter | calcMod | Pythagoras Interactive |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (1 ratings) | 5.0 (1 ratings) |
| Positive reviews | 100.0% of reviews | — |
| Number of ratings | 1 | 1 |
| Update frequency | Every 18 months | Every 2 weeks — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPod | iPhone, iPad |
| Requires iOS | 15.0 — better | 16.0 |
| Further details — not scored | ||
| Size | 1 MB | 1 MB |
| Age rating | 4+ | 4+ |
| Developer | Alain Cardinaux | ALAN PETERSON |
Customer experience
calcMod
Pythagoras Interactive
In-app purchases
calcMod
No in-app purchases
Pythagoras Interactive
No in-app purchases
Questions
Is calcMod free?
Is Pythagoras Interactive free?
Which has better reviews, calcMod or Pythagoras Interactive?
Do calcMod or Pythagoras Interactive have ads?
Which is updated more often, calcMod or Pythagoras Interactive?
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