Abaco vs Sumday

Abacus Flash Mental Math Training The best flash mental math app to improve your calculation skills anytime, anywhere! Start practicing immediately with default settings or customize everything to your preference. Ideal for mental math competition prep, brain training, and improving math skills. A proven app experienced by over 20,000 users! Key Features: Two Practice Modes • Addition/Subtraction Mode: Step-by-step addition and subtraction practice • Multiplication/Division Mode: Systematic multiplication and division mental training Designed for Abacus Mental Math • Built-in difficulty adjustment algorithm prevents problems from becoming too easy • Subtraction problems are designed so answers never go negative • Division problems always result in whole numbers • Optimized for flash training, similar to abacus competition programs Convenient Customization • Addition/Subtraction Mode: 1-8 digits, 2-200 problems • Multiplication/Division Mode: 1-8 digits × 1-8 digits • Speed control (0.1s-30s) • Custom theme color support • Presets: save and load your favorite settings instantly Multi-language Support • 40+ languages: English, Korean, Japanese, Chinese, Spanish, German, French, and more • Intuitive interface for all languages Recommended for: • Teachers running abacus/mental math schools • Students learning abacus/mental math • Adults seeking brain training • All ages wanting to improve math skills • Those wanting to develop concentration and calculation abilities Experience amazing improvement in mental math skills with just a few minutes of practice daily! With your permission, install and usage events and an app-instance ID are sent to Google Analytics to measure app use and ad performance. No advertising ID or personalized ads. Optional; change this anytime in App Info.

Five minutes a day to get your mental math back. Sumday is a quiet daily routine for adults: real arithmetic, not puzzles, that keeps your number sense sharp. The more we rely on calculators and spreadsheets, the slower the math in our head gets. Sumday wakes it up with one short set a day that mixes addition, subtraction, multiplication, division, percentages and estimation. Learn one practical math trick a day, the kind school never taught you, and feel your speed come back. WHO IT'S FOR • Adults who feel their mental math isn't what it used to be • Anyone preparing for aptitude or job tests with timed number questions • People who want to split a bill, work out a discount or estimate a total in seconds • Anyone looking for light daily brain training HOW IT WORKS 1. Solve today's set of 20 questions. Five minutes is enough. 2. Check your results: accuracy and response time, compared with yesterday. 3. Unlock today's technique card and use it in tomorrow's set. 4. Come back tomorrow. A daily reminder keeps your streak going. FEATURES • Today's set: 20 mixed arithmetic questions across 7 types: addition, subtraction, multiplication, division, percentages, estimation and everyday math • Adaptive difficulty: questions get harder as you improve and ease off when you get stuck (12 levels) • Daily technique cards: 30 mental math tricks, from rounding shortcuts to quick percentages • Results report: accuracy, average response time and change since yesterday on one screen • Progress charts: daily and weekly trends in accuracy and speed • Streaks and a gentle daily reminder NO ACCOUNT, NO SERVER No sign-up needed. Your records stay on your device, and it works in airplane mode. PREMIUM (OPTIONAL) A one-time purchase removes ads and unlocks 3 practice modes (estimation, percentages, everyday math), Challenge mode (endless survival with 3 lives), Master mode (one life, every question timed), detailed statistics and all 30 technique cards. No subscription. Available in English, Korean and Japanese. Start your five minutes of math practice today.