Abacus vs Flash

WHEN ANCIENT WISDOM MEETS MODERN TECHNOLOGY ! BEAUTIFUL INTERFACE with COMFORT & BIG BEADS ! SUPPORT DECIMAL POINT & NEGATIVE NUMBERS ! 21-COLUMN ABACUS CAN SPEAK ! • LANGUAGES: ENGLISH JAPANESE RUSSIAN CHINESE ARABIC GERMAN FRENCH SPANISH KOREAN NORWEGIAN FINNISH CANTONESE DANISH PORTUGUESE SWEDISH INDONESIAN TURKISH DUTCH VIETNAMESE • LET'S USE ABACUS TO CALCULATE AND HAVE FUN ! 2+2+2+2+2+2+2+2+2+2 = 20 30-3-3-3-3-3-3-3-3-3-3 = 0 1+2+3+4+5+6+7+...+98+99+100 = 5050

Train your mental arithmetic with numbers that flash one at a time. Watch the sequence, add it in your head, and enter the total before the next round. Flash keeps practice simple: • Choose 1–7 digits and 2–500 numbers. • Set the display speed from 0.1 to 3.0 seconds. • Practice 1–999 rounds or keep going in Infinite mode. • Turn answer input and automatic continuation on or off. • Choose a light or blue background. • Use sound, haptic, or both for feedback. • Save your favorite settings as presets. • Check accuracy, response time, streaks, and total training time. • Review the exact number sequence for each round and retry mistakes. Use it for a quick session or a longer challenge. Flash gives you a clear way to practice at your own pace.