Every tap is logged
Number, time-since-start, and whether it was the next expected number. Not the answer — the trajectory.
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A Single Probe · Demonstration
Count to 100 by ones and tens
K.CC.A.1 · Hundred-board count-trail
This is what one probe in The Star Atlas Library will feel like. Tap a few numbers in order, then press Done. The engine reads your trajectory — not just whether you got things right — and shows what it would write into the mastery passport.
The Task
Tap each number in order from 1 to 100.
Tap next
1
Counted
0 / 100
Slips
0
Tap at least 8 numbers in order to finish, or reach 100.
Why a Probe Is Not a Test
The trajectory tells the truth
Self-correction is mastery
A learner who slips on 13, notices, and continues with 14 shows mastery — not a deduction. (Rule R3.)
Fast and right is fluency
Speed is never penalized. Only fast-and-wrong counts as a guessing signal. (Rule R6.)