(Open Source) Mental Math vs OnlyMath

A free, open-source mental math trainer. No ads, no paywalls, no locked content — every exercise and difficulty is included. Sharpen your arithmetic with quick timed tests, custom drills, and a library of mental-math tricks. Everything runs offline and your progress stays on your device. FEATURES Timed Tests A daily 60-second challenge plus sprints, a two-minute marathon, per-operation tests, and a hard mixed test — at four difficulty levels, each with best scores. Custom Trainer Pick a number domain (Times tables, Natural, Decimal, Money, Huge), choose one or more exercises, and set per-exercise difficulty from Easy to Super hard. All the Operations Addition, subtraction, multiplication, division, squares, square roots, fractions, percentages, and modulo. Mental Math Tricks Dozens of step-by-step tricks for faster addition, subtraction, multiplication, division, and squares — with worked examples and favorites. Practice Any Trick Every trick comes with a 60-second drill built for it: × 11 drills, squares ending in 5, numbers near 100, and more. Magic Square A number puzzle: make every row, column, and diagonal add up to the same total. Four levels, from 1-9 up to bigger number sets. Progress Tracking Solved totals, accuracy, best run, daily streak, longest streak, and a weekly activity view. Fast Sessions An on-screen keypad with instant answer checking and haptics. No ads. No paywalls. No account required. 100% Open Source The complete source code is public - see it, audit it, or contribute at https://github.com/Open-Apps-Studio/mental-math

Only Math is a simple, focused mental math app built for straightforward practice. Train addition, subtraction, multiplication, division, or mixed operations across five difficulty levels. Choose between Standard and First Try modes, select your round length, and track your speed, accuracy, personal records, streaks, and daily practice. Designed for students, professionals, interview preparation, and anyone looking to sharpen their mental math skills or quantitative abilities. No accounts. No subscriptions. No ads. No useless features. Only math.