Goldbach's Conjecture Math
Education
Free · In‑App Purchases · Designed for iPad. Not verified for macOS.
Meet the new Learn tab: 30 lessons, daily practice and interactive prime explorers. Your calculator stays free. Explore more with optional Goldbach Plus.
A little curiosity. A world of numbers.
Explore Goldbach’s conjecture with your free prime-pair calculator, and take your curiosity further with a new Learn tab.
YOUR CALCULATOR STAYS FREE
Find one or up to 20 prime pairs, enter numbers up to 35 digits, keep history, save favorites and share results. No ads or app account required.
30 LESSONS, THREE PATHS
Learn about primes, divisibility, factorization, modular arithmetic, Miller–Rabin, Euclid, twin primes, RSA and mathematical proof. Each lesson includes explanations, a worked example and a quiz with feedback. Lessons 1–5 are free.
A DAILY SPARK
Answer a free daily question, build a streak, bookmark lessons and track your progress. Goldbach Plus adds unlimited practice with instant explanations.
EXPLORE THE LAB
The interactive prime sieve up to 100 is free. Plus adds the Ulam spiral, prime-gap charts, Goldbach pair-count charts, CSV export and a factor explorer. Lab calculations use exact methods within their displayed small ranges.
GOLDBACH PLUS
Monthly and annual auto-renewing subscriptions unlock all 30 lessons, unlimited practice and the complete Lab. Both plans provide the same access. The existing calculator, history, favorites and sharing remain free. Prices and billing periods are shown before purchase. Payment is charged to your Apple Account. Subscriptions renew unless canceled at least 24 hours before the current period ends. Manage or cancel in App Store account settings. Restore active purchases in the app.
PRIVATE BY DESIGN
Lessons and math explorations work offline. Calculations and learning progress stay on this device. Progress does not sync between devices. Apple handles purchases. No tracking or advertising SDKs.
Mathematical experiments do not prove the conjecture. Large-number factors may be probable primes rather than certified primes.
Privacy & support: https://oanarinaldi.com/goldbachprivacy.html
Terms: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
Meet the new Learn tab: 30 lessons with worked examples and quizzes; five free introductory lessons; a free daily challenge and interactive sieve; local progress, bookmarks and streaks.
Optional Goldbach Plus monthly and annual plans unlock the full lesson library, unlimited practice, Ulam spiral, prime-gap charts, Goldbach atlas with CSV export and factor explorer.
Also includes a refreshed calculator, safer large-number primality tests, responsive cancellation and favorites fixes. Your existing calculator, history, favorites and sharing remain free.
The developer, OANA RINALDI, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- OANA RINALDI
- Size
- 2.1 MB
- Category
- Education
- Compatibility
Requires iOS 26.0 or later.
- iPhone
Requires iOS 26.0 or later. - iPad
Requires iPadOS 26.0 or later. - Mac
Requires macOS 26.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 26.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- Goldbach Plus Annual $19.99
- Goldbach Plus Monthly $2.99
- Copyright
- © Oana Rinaldi