Number Theory Lab

Interactive solvers, step-by-step derivations, and a theory guide for elementary number theory.

A Chrome extension for elementary number theory: nine interactive solvers, each showing its full derivation rather than just an answer, backed by exact arbitrary-precision arithmetic. Solvers: • Extended GCD & LCM — Euclidean algorithm, Bezout identity • Linear Diophantine equations • Linear congruences (ax ≡ b mod m) • Modular polynomial roots • Euler totient φ(n) & residue systems • Prime factorisation & divisors (τ, σ, Möbius μ) • Chinese Remainder Theorem • Modular exponentiation & multiplicative order • Quadratic residues & Legendre symbol Also included: • A formula workbench for exploring sequences (perfect squares, Fermat primality scans, modular sweeps) • A searchable theory guide with definitions, theorems, and external references • Calculation history you can save and reload Privacy: this extension requests no permissions and makes no network requests. Everything — including math fonts — is bundled; nothing is fetched, tracked, or sent anywhere. All history and preferences stay in your browser's local storage.