Mental math

Type a drill like 75x2d and get endless questions from it. Every answer is timed and every run is kept, so you can see whether you're really getting faster. It also trains the Major System for memorizing numbers.

How to write a drill

A drill is a pattern, and each pattern produces endless random questions. Separate several with commas and each question comes from one of them.

You type	Meaning	Example	Answer
`75x2d`	75 × any 2-digit number	75 × 48	3,600
`2dx2d`	2-digit × 2-digit	37 × 82	3,034
`75x2..4d`	75 × a 2-, 3- or 4-digit number	75 × 2270	170,250
`10..99x7`	a range, both ends included	63 × 7	441
`3d^2`, `2d^3`	squares, cubes	417²	173,889
`4d/1d`	division with remainder	8231 ÷ 6	1371 r5
`3d+3d`, `3d-3d`	add, subtract (bigger first, so never negative)	812 − 345	467
`75x2d,25x2d`	a mix of parts	either one

75 is a fixed number, 2d any 2-digit number (1d is 2 to 9), 2..4d a number with 2 to 4 digits and 10..99 a range.
You can type * or × for x, ÷ for /, spaces anywhere, and 2-4d for 2..4d.
Answers accept 3,600, 3 600 and 3600. For division, 1371 r5 or 1371 rem 5, or just 25 when nothing is left over.
Two fixed numbers (7x8) isn't a drill: it would always ask the same thing.

Modes

75x2d: practice, until you stop.
75x2d 20: a 20-question benchmark. Your best is the fastest total time, and only perfect runs count.
75x2d s: a 60-second sprint. Your best is how many you get right. An answer after the minute is up doesn't count.
While answering, s skips (counts as wrong) and q stops. Esc stops too.

The menu

Every drill you run joins a numbered list showing your accuracy (green from 90%, yellow from 70%), average time per correct answer, number of runs, best sprint (⚡) and best perfect benchmark (⏱20:96s).

1, 1 20, 1 s: run drill 1 in each mode.
h: your last 30 runs, by day. h 2: drill 2's runs and what you missed.
mix 1 3: mixes drills 1 and 3 into a new one.
del 2: removes drill 2 from the list (its history stays).
major, seq: your peg table and your sequences.
export: downloads everything (drills, history, pegs and sequences) as one JSON file.

Major System

Each number from 0 to 9 and from 00 to 99 gets a word (its peg). You keep them in major as plain text, one per line: 36 Mago/a (from Oz). Text in parentheses is a reminder and isn't graded; Mago/a accepts mago and maga, and the first word alone is enough. Accents and case don't matter. Lines starting with # are comments.

You type	It shows	You answer
`peg`	a number	its word
`word`	a word	its number
`mem6`, `mem4..10`	digits in pairs until you tap Got it, then hides them	the digits, from memory
`enc6`	digits in pairs (only pairs that have a peg)	one word per pair
`dec6`	the words	the number

Miss a memory drill and it shows you the pegs for those digits.
Type 36 -> mago (or 36 = mago) at any prompt, even mid-question, and the peg changes on the spot. The time you spend changing it isn't counted.

Sequences

seq add pi 3141592653 saves a sequence; seq del pi removes it; seq lists them with their words.
learn:pi: study the digits with their words, then recall them. Miss and it tells you where: “first slip at digit 7: 26 = Nacho”.
seq:pi: recall it without studying first.
enc:pi: type its words against the clock, in 10-digit blocks, in order.

Your data

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