Brain training, one drill at a time
Eight exercises, each training one specific mental skill.
No lectures, no worksheets — just a short, focused drill for one skill at
a time: math facts, working memory, attention, estimation, reading
recall, task-switching, and inhibitory control.
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No account needed for the free exercise. It stays free.
How it works
One skill, one drill
Each exercise trains exactly one thing — a math fact, a running
total, a sequence of squares — so there is never any doubt about
what got better.
Ranks, not scores
Most exercises use a simple rank ladder that moves with real
performance, not time spent. Get sharper, rank up.
Nothing is collected
No analytics, no tracking, no learner accounts. If you sign in, the
account belongs to you, the adult.
Exercises available now
Free forever working-memory updating (verbal/numeric) — holding and updating a running total across a chain of steps.
Track a running total through a chain of plus and minus steps, entirely in your head.
What this trains
Sign in to open math-fact fluency via retrieval practice / spaced repetition (a 3-box Leitner system).
Drill multiplication facts with a spaced-repetition system that shows your weak spots more often.
What this trains
Sign in to open attention to detail / error-spotting (proofreading under time pressure).
Spot the one wrong number hidden in a receipt, under time pressure.
What this trains
Sign in to open spatial working memory (a Corsi-block-style sequence recall task).
Watch a sequence of lit-up squares, then tap them back in the same order.
What this trains
Sign in to open estimation and magnitude judgment, with a commit-before-reveal structure (state your guess before seeing the true value, forcing genuine estimation rather than adjustment).
Estimate a real number before it's revealed, and see how close your gut gets.
What this trains
Sign in to open reading comprehension via retrieval, not re-scanning (the passage is not visible while answering).
Read a short passage, then answer questions about it from memory alone.
What this trains
Sign in to open cognitive flexibility / task-switching (the "switch cost" paradigm from cognitive psychology).
Switch between two rules on the fly and see the cost it takes on your reaction time.
What this trains
Sign in to open inhibitory control / selective attention (a classic Stroop color-word interference task).
Name the ink color, not the word — a classic test of ignoring what a word says.
What this trains
Where this is up to. BrainGym is early. All eight
exercises are live and finished: The Ledger is free for anyone, and the
other seven open with a sign-in.