math
Tools for numbers: mental arithmetic, the Major System and the digits of π. No accounts, no servers: everything stays in this browser.
| page | contents |
|---|---|
| /en/arithmetic/ | Mental arithmetic trainer. Drills as patterns (75x2d, 4d/1d, 3d^2); practice, benchmark and 60 s sprint; history and records. |
| /en/major-system/ | Major System: peg table 0–99, number ↔ word drills, digit memory and sequences. |
| /en/pi/ | Digits of π: a challenge up to a goal, and pair-by-pair practice with the first 1000. |
Data
/arithmetic/ and /major-system/ share drills, history, pegs and sequences. /pi/ keeps its record and position. All in localStorage; nothing is sent to a server.