Simulator scope
The homepage calculator is an educational TI-84 style practice interface, not a hardware-perfect device emulator.
It focuses on expression entry, key layout familiarity, graph support, history, and workflow reinforcement.
Graph explorer
The graph explorer estimates zeros, extrema, and inflection-style points numerically to support study and practice. These approximations are educational aids, not symbolic proofs.
AI helper
The AI-style helper is a front-end explanation tool for common equation forms. It is intended to explain likely steps and TI-84 style button paths for practice.