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A mental math trainer for unit conversions. Each round gives you a value to convert — type your best estimate using the calculator keypad and press = to submit.
No calculators, no looking up formulas (well, the 𝑓 button is there if you need a hint). The goal is to build intuition for real-world unit conversions.
Each answer is graded into one of four tiers based on your % error. The tier earns a fixed score, and your session average is the mean of those scores — so 75% means you were consistently hitting Close.
The margin for each tier varies by category — conversions that demand precision (data, angles) have tighter windows than rough real-world ones (nautical, power).
📚 Practice — Unlimited questions at your own pace. Best for learning new conversions.
⏱ Timed — Answer as many as you can before time runs out. Choose 10–300 seconds.
Select specific conversion pairs to drill exactly what you need. Tap a category to expand it, then check individual conversions. Selected pairs appear as pills you can remove anytime.
During a game, tap 𝑓 to reveal the formula as a hint. Tap ‹ Menu or END to exit early.