Age
4+
Seller
Haruhiko Kishi
About this app
Made for iPhone Duo. Half open like a laptop, numbers flash on the top screen and the bottom becomes your number pad. One screen to watch, one to type. Kyu 10 to Dan 20.
Practice flash anzan (flash mental arithmetic) in the same format as the Japanese grading exam—and climb the ranks.
GRADED MODE (30 RANKS, KYU 10 TO DAN 20)
Each rank uses the exam's total-time format: numbers flash within a fixed total time, you answer 10 problems, and 70 points is a pass.
YOUR GRADE IS KEPT
Your best rank is recorded on the device and in iCloud, so it follows you to a new device.
ANSWER BY VOICE
Type on the number pad, or just say the answer. Speech recognition runs entirely on your device—your voice is never sent anywhere.
CUSTOM PRACTICE
Set digits, count, and display time yourself—from slow single digits to 3-digit numbers at 0.3 seconds.
IPHONE DUO
Big numbers when it's open; fold it in half and the question sits above with the number keys below. Close it and keep practicing on the outer screen.
IPHONE, IPAD AND MAC
Works on iPhone, iPad and Mac, and your grade follows you between them through iCloud.
No ads. Available in nine languages: English, Japanese, Chinese (Simplified and Traditional), Korean, German, Spanish, French and Brazilian Portuguese.
Note: This app is not affiliated with or endorsed by any certification body.
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Screenshots
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What's New · v1.3.7 · Oct 17, 2026▾
Works with iPhone Duo. Fold it in half: the answer on top, the number keys below.
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