Quant interview prep guides

Mental Math and Estimation Final Checklist

Final checklist for mental math and Fermi estimation prep, covering arithmetic, statistics, market-making math, Fermi prompts, mocks, and review.

Candidates finishing mental math and estimation prep.

Arithmetic readiness

Fractions, percentages, multiplication, division, weighted averages, EV arithmetic, and units should be accurate before final mocks.

Statistics and market math

Review z-scores, variance, standard deviation, correlation, midpoint, spread, probability price, inventory, and simple PnL arithmetic.

Fermi readiness

For estimates, define target units, decompose drivers, use ranges, check scale, and identify the dominant assumption before presenting the final number.

Mock readiness

Run at least one mixed mock where arithmetic, estimation, and explanation happen together. Review the error categories immediately.

Common mistakes

Candidates often treat checklists as passive review. Use each unchecked item to assign a live drill before moving on to another topic.

Practice the pattern

Use the LeetQuidity curriculum and calibration to turn this topic into a focused practice plan.