Goldbach’s Conjecture Math

A little curiosity. A world of numbers.

Explore one of mathematics’ most beautiful unanswered questions: can every even integer greater than 2 be written as the sum of two primes?

YOUR CALCULATOR STAYS FREE
• Find prime pairs for even numbers, with inputs up to 35 digits.
• Choose a single pair or search for up to 20 pairs.
• Keep calculation history, save favorites and share results.
• No ads and no app account required.

LEARN SOMETHING WONDERFUL
Follow 30 short, original lessons through three paths: Foundations, Patterns & Powers, and The Bigger Picture. Each lesson includes a clear explanation, a worked example and a quiz with feedback. Start with five free lessons on primes, divisibility, trial division, the sieve and Goldbach’s conjecture.

BUILD A DAILY HABIT
Try a free daily question, track a practice streak, bookmark lessons and watch your learning progress grow. Goldbach Plus adds unlimited practice with instant explanations.

MAKE A DISCOVERY IN THE LAB
Use the free interactive sieve to reveal the primes up to 100. With Plus, explore the Ulam spiral, chart prime gaps, count all Goldbach pairs within small ranges, export chart data as CSV, and unpack numbers with the factor explorer.

GOLDBACH PLUS
Choose a monthly or annual auto-renewing subscription. Both plans unlock all 30 lessons, unlimited practice and the complete Lab. The existing calculator, history, favorites and sharing remain free. Prices and billing periods appear before purchase. Payment is charged to your Google Play account at confirmation. Subscriptions renew automatically unless canceled. Manage or cancel in your Google Play subscription 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. Google Play handles subscription transactions. No tracking or advertising SDKs.

Mathematical exploration is not a proof of the conjecture. Large-number factors may be probable primes rather than certified primes. The Lab uses exact methods within its displayed small ranges.

Privacy & support: https://oanarinaldi.com/goldbachprivacy.html
Terms of use: https://play.google.com/intl/en_us/about/play-terms/

Recent changes:
A completely rebuilt Goldbach experience: a free 35-digit prime-pair calculator, history, favorites and sharing; 30 original lessons, quizzes, daily practice and local progress; and five interactive number theory explorers. Goldbach Plus adds the full lesson library, unlimited practice and the complete Lab.