All top consulting firms require candidates to be able to solve numerical problems with just pen and paper during both case interviews and the screening test before interviews.
Many candidates feel that their numeracy skills have become a little rusty after years of using Excel or calculators. To add to the rustiness, candidates are rarely prepared for the added pressure of having an interviewer look over their shoulders as they perform multi-step calculations.
So, to help you brush up on your numeracy skills, here are a few tips and resources.
Brush up on your arithmetic
To make sure you’re prepared for the vast majority of the potential questions, be sure to brush up your skills for solving basic and common arithmetic operations:
- Addition
- Subtraction
- Multiplication
- Division
- Percentage
- Percentage of percentage
- Fraction simplification
There are many opportunities to practice these operations in everyday life. For example, you can calculate percentages based on train stations left on your journey, laps completed on the treadmill, your share of a restaurant bill, or headline figures on your morning paper. But if you want to implement a more aggressive regimen, spend 10 minutes a day practicing using the calculation drills we’ve developed inside the Interview Prep Course.
Once you’re comfortable with your arithmetic, revisit some more advanced concepts such as weighted average, factoring, expected value, squares, and compounding and discounting.
Brush up on your business math
Practicing common math operations will only get you so far. You’ll also need to know what these math problems look like in a business context, which means you should familiarise yourself with:
- Profit and loss sheets
- Balance sheets
- Market and market share
- Compound growth rates
- Break-even calculations
- Discounted cash flow
- Net present value
Once you fully understand and can use each of these, you’re in a good place to handle the vast majority of math you might come across in a case interview.
Practice case math
Practicing math in the context of cases is important, as it allows you to test your skills under pressure within a real case scenario. We recommend that you use a combination of all the following approaches to practice math in the context of cases:
- Invest some time in practicing solving case math problems on your own. Our Interview Prep Course includes drills that are designed to help you practice all the elements of case math, from requesting missing data and setting an approach to calculating the solution and interpreting the results.
- Practice market sizing and estimation questions. These cases require you to structure a mathematical approach, make assumptions and perform various calculations to come to a numerical answer. The good news is that tackling market sizing and estimation cases is something you can practice; our Interview Prep Course includes 12 estimation and market sizing cases for you to try as part of your live case practice sessions with a partner.
- Complete at least 25 live case interviews that involve math problems, so you can get a feel for what solving math on the fly feels like and identify any weaknesses that might require more focused preparation.
