Percentages
Use 10%, 5%, and 1% anchors for margins, growth, and conversion rates.
Open guideInterview Prep
Case Interview Math Practice
Build the fast, reliable arithmetic used in consulting cases: percentages, growth, breakeven, market sizing, profitability, unit economics, and averages.
Quick Answer
Practice basic arithmetic under time pressure, then layer business prompts on top. Most case math mistakes come from rushing setup, dropping units, or losing accuracy on simple percentages and division.
Market sizing
Translate prompts into population x penetration x frequency x price.
Open guideCAGR and growth
Estimate growth rates with Rule of 72 and benchmark compounding patterns.
Open guideBreakeven
Compute contribution per unit first, then divide fixed cost by contribution.
Open guideUnit economics
Practice CAC, payback, margin, and LTV-style arithmetic with clear units.
Open guideAverages
Build speed on division, weighted averages, and reasonableness checks.
Open guideUse This 10-Minute Drill
- Two minutes: medium mixed arithmetic warm-up.
- Six minutes: focus on the operation that slows your cases down.
- Two minutes: timed benchmark and note one mistake pattern.
For worked examples, start with case interview math questions and market sizing examples.