FREE0+0ACC--
← All practice guides

Interview practice

Citadel Securities-style 80-in-8 mental math practice

A market maker quoting across equities, options, fixed income and ETFs globally.

What this assessment looks like

A speed-arithmetic screen: on the order of 80 questions in 8 minutes, so roughly six seconds per answer. Addition, subtraction, multiplication, division, fractions, decimals and percentages, often with negative marking - a wrong answer costs more than a skip.

  • Two-digit multiplication and division without writing anything down
  • Fraction and decimal conversion at a glance
  • Percentage moves in both directions (a 20% drop needs +25% to recover)
  • Knowing when to skip: negative marking punishes guessing

Train it here

  • Arithmetic Drill - 2.5 timed minutes of exactly this question mix, with a ghost of your best past run to race.
  • Dino Dash - Endless mental-math runner - one mistake ends the run, and the questions climb through ten difficulty tiers.
  • Sequence Sprint - Pattern recognition under the same per-question time pressure.

Also reported at Citadel Securities

Number sequences · Probability & estimation · Market making · Quant developer coding · Stochastic processes

Outcry is not affiliated with Citadel Securities and has no access to their assessment content. This page describes formats candidates publicly report, and the drills here train the underlying skills - they are not the firm’s questions.