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8 DRILLS · MENTAL MATH · ORDER OF MAGNITUDE · PATTERN RECOGNITION · TASK SWITCHING · AGAINST THE CLOCK   8 DRILLS · MENTAL MATH · ORDER OF MAGNITUDE · PATTERN RECOGNITION · TASK SWITCHING · AGAINST THE CLOCK   
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LAB 12 · DRILL LAB

Mental math practice for quant interviews

Timed speed arithmetic, Fermi estimation and sequences - negative-marked like Optiver's 80-in-8.

TICKETS
0
ACCURACY
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#
DRILL
SKILL
LENGTH
YOUR HI
LAST 8
01
Arithmetic Drill2.5 minutes of addition, fractions and decimals - solo or racing a recorded past run
MENTAL
MATH
2:30
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NOT PLAYED
PLAY
02
Fermi EstimationPiano tuners in Chicago, atoms in a body, golf balls in a bus
ORDER OF
MAGNITUDE
10
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NOT PLAYED
PLAY
03
Sequence SprintRead the rule hidden in a list and enter the next value before it slips
PATTERN
RECOGNITION
15
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NOT PLAYED
PLAY
04
Duck Duck DashAn endless run through a sunny field - one collision ends it
MENTAL
MATH
∞
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NOT PLAYED
PLAY
05
Likelihood RankingOrder events from most to least likely - the “which is most likely” screen question
PROBABILITY
RANKING
12
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NOT PLAYED
PLAY
06
Crossroad MultitaskerTrack the arrows and the parity at once - the question keeps switching on you
TASK
SWITCHING
∞
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NOT PLAYED
PLAY
07
Flappy MathFly through the gap with the right answer, then hop mismatched colours - the mode keeps switching
TASK
SWITCHING
1:30
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NOT PLAYED
PLAY
08
Deep ShiftBinomials, poker forge, Bayes reactor, first signals, and the normal curve with confidence calibration
PROBABILITY
CALIBRATION
5:00
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NOT PLAYED
PLAY
NO GRADED ANSWERS YET - EVERY DRILL SCORES EVERY REP> PICK A GAME

What the Drill Lab games train

Arithmetic Drill

A 20-card flashcard race across twelve arithmetic categories - play solo or race a ghost recording of a real past run. Read the Arithmetic Drill guide.

Fermi Estimation (Classic)

Quote a low-high range on ten real-world estimation questions - points for containing the truth, more points for a tight range. Read the Fermi Estimation (Classic) guide.

Sequence Sprint

Find the rule and type the next number - freshly generated arithmetic, geometric, square, alternating, and Fibonacci-style sequences. Read the Sequence Sprint guide.

Duck Duck Dash

An endless runner through a sunny field where the only way to hop is answering a mental-math question - one collision ends the run. Read the Duck Duck Dash guide.

Likelihood Ranking

Order outcomes from most to least likely - student score tables, distributions, dice and card events, Poisson arrivals, urns, and scatter plots. Read the Likelihood Ranking guide.

Crossroad Multitasker

A duck at a 4-way crossroad and four corner math pods - answer whichever question is live as it switches unpredictably between the two streams. Read the Crossroad Multitasker guide.