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Quant Mental Math Trainer
30-second timed drills that mirror the tests and interviews at Citadel, Jane Street, Optiver and other top quant firms
⚡ High-frequency mental math for quant traders
A 30-second drill inspired by screening tests at proprietary trading firms such as Optiver and Flow Traders. See how many two-digit multiplication questions you can solve under pressure.
Why do quant interviews test mental math?
Traders at quant firms (Citadel, Jane Street, Optiver, Flow Traders) make fast real-time decisions, and mental math is a baseline requirement. Written tests and interviews give you timed calculations — typically a two-digit multiplication every 1.5 seconds.
What the written tests expect
- Speed: no more than 1.5 seconds per question on average
- Accuracy: above 90%
- Formats: two-digit multiplication, percentages, probability estimates
How to get faster
Consistent practice is the key. 10–15 minutes of intense daily training shows clear gains within 2–4 weeks. Keep a few tricks handy, for example:
- Distribution: 23 × 8 = (20 + 3) × 8 = 160 + 24 = 184
- Rounding: 19 × 7 = (20 − 1) × 7 = 140 − 7 = 133
- Quick percentages: 40% = 4/10 = 2/5 (simplify the fraction)