Mental Math Tricks vs Double Digits

MathMind teaches you real mental math techniques - not gimmicks, not drills you'll forget tomorrow. Learn the same shortcuts used by mathematicians, chess players, and memory athletes to calculate faster than a calculator. 30 PROVEN TRICKS, 7 CATEGORIES: Master techniques across every major area of mental arithmetic: - Multiplication: square numbers ending in 5, multiply by 11, multiply two-digit numbers instantly - Division: divisibility rules, divide by 5, divide by 25 - Squares and roots: square any two-digit number, estimate square roots - Percentages: the percentage flip trick, tips in seconds, compound growth - Fractions: convert, compare, and calculate - Addition and subtraction: round-and-adjust, left-to-right addition - Advanced: day of the week for any date, digit sums, cube estimation THREE WAYS TO LEARN: LEARN - Each trick has a clear explanation, worked examples with step-by-step walkthroughs, and a "Why does this work?" section that shows the underlying math. PRACTICE - Drill any trick with infinite auto-generated problems. Track your accuracy, streak, and solve time as you improve. CHALLENGE - Timed tests across all tricks you've learned. Compete against your own best. Take the Daily Challenge - the same problems for everyone, every day. BUILT FOR REAL PROGRESS: - Speed graphs: watch your solve time drop week by week - Day streaks: build a consistent practice habit - Category breakdown: see exactly where you're strong and where to focus - Combo multipliers: chain correct answers for bonus scoring - Haptic feedback and smooth animations HONEST PRICING: MathMind is free to download with 5 foundational tricks unlocked. Unlock all 30 tricks with a single one-time purchase - no subscriptions, no ads, no data collection, ever. PRIVACY FIRST: Your progress stays on your device. MathMind has no accounts, no sign-ups, no analytics, no trackers, no ads. Nothing leaves your phone, unless you manually share it. Whether you're a student preparing for exams, a professional who wants to run mental calculations in meetings, or just someone who enjoys training their brain - MathMind gives you the tools to think faster. Download and start learning in seconds!

How fast can you solve 7 × 38 in your head? Double Digits is a drill for people who want to multiply two-digit numbers quickly. CONQUER EVERY NUMBER FROM 1 TO 99 The home screen is a grid of the numbers 1 to 99. Pick one and you get all 90 combinations of that number with every two-digit number, from 10 to 99. Solve them all and the number is cleared. Each cleared number keeps your best time. Filling in all 99 is the goal. WATCH YOURSELF GET FASTER Take on the same number again and your times are drawn as a line chart. The horizontal axis is your attempt number, the vertical axis is your finishing time. A line sloping downward is progress you can see. The days you practice are recorded automatically, along with your current streak. PRACTICE ANY COMBINATION Want to drill only 7 and 8, and only against the 20s? You can pick exactly which numbers to learn and what to multiply them by, so you can attack your weak spots directly. INPUT THAT KEEPS UP The keypad handles multiple fingers at once, so nothing is dropped no matter how fast you type. Correct answers give a light haptic tap and a sound, then move straight on. COMPETE GLOBALLY Leaderboards are supported through Game Center, with a separate board for every number. Signing in is optional; decline it and every practice feature still works. Light and dark appearance are both supported, following your device setting automatically.