Free public beta until December 4, 2026: every course is open, no card needed. After that, the first chapter of each course stays free and full access is a one-time $39 ($19 for up to 100 founding members chosen for helpful feedback). Your progress is kept. How the beta works

🧮

Functions Sprint

Evaluate a floor or ceiling, then decide whether a listed function is one-to-one -- read the outputs, don't guess.

⏱️ 90s

▶ Log in to play

← Back to the arcade