Mental Math vs (Open Source) Mental Math

10 minutes a day to keep your mental math sharp. Whether you're in middle school, in high school, or an adult who wants to reconnect with math, Kalc helps you forge solid mental reflexes, without cramming. Spaced repetition system (SRS): concepts you master space out over time, the ones you miss come back the next day. The method known to deliver the most learning per minute practiced. WHO IT'S FOR · UK students (Year 7-10), US students (Grade 6-9) · Other English-speaking systems (Canada, Australia, Ireland, NZ) · Spanish-speaking students (Spain ESO, Mexico secundaria/preparatoria) · French-speaking students (France, Belgium, Switzerland, Quebec) · Adults who want to get back fluency with mental math Each user picks their school system during onboarding. Content and examples adapt. WHAT KALC COVERS · Multiplication and division (times tables, decimals, signed) · Fractions (simplification, operations, fraction of a whole) · Percentages (calculation, increase, discount, compound change) · Powers and square roots · Algebra and order of operations · Addition and subtraction of signed integers TWO PRACTICE MODES · Zen mode: at your own pace, no pressure, to consolidate the basics · Chrono mode: against the clock, to build speed under exam conditions VISIBLE PROGRESS Every skill has its own level and progress bar. You see exactly where you stand and what's left to master. IN REAL LIFE Every session ends with a concrete example of how this skill serves you day to day: splitting a restaurant tab, reading a paycheck, working out a discount, planning a budget. Mental math is something you actually use. HOME SCREEN WIDGETS Track your progress straight from your iOS home screen, without opening the app. Streak, XP and skills in progress at a glance. MEASURED REMINDERS Up to 5 reminders over the first 3 weeks, off at any time. No spam, no guilt-tripping. ONE-TIME PURCHASE, NO SUBSCRIPTION Kalc is free to download (1 skill available without purchase). Full access unlocks with a single purchase (lifetime or 1 year non-renewing). No traps, no hidden paywall. PRIVACY All your data stays on your device and syncs through your personal iCloud account. No ads, no advertising tracking, no cookies. Kalc is for people who want real progress in mental math. Privacy policy: https://lmtdigitalcreations.com/kalc/privacy.html Terms of use: https://lmtdigitalcreations.com/kalc/terms.html

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 — 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. 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, haptics, and sound. 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