 Introduction: Overview and Background

Introduction & Background

Context of Quant Problems in Case Interviews

Math Skills Required for Case Interviews

Course Requirements and Math Review (Optional)
 FastMath: Multiplication & Division

FastMath Overview

Multiplication

Division & Factoring — Part 1

Division & Factoring — Part 2

Multiplication & Division Practice Problems

Mental Math Regular Exercises
 Detail: Multiplying & Dividing by "Clean" Numbers

Multiplying & Dividing by 25

Multiplying & Dividing by 5 & 50
 FastMath: Percentages & Percentage Growth

Percentage Calculations

Percentages & Compound Growth  Part 1

Percentages & Compound Growth  Part 2

Percentages & Compound Growth  Part 3

Inverse Proportion

FastMath Tables
 Quant Case Problems

Quant Case Problems Overview

Breakeven Analysis — Problem 1

Profitability Analysis

Breakeven Analysis — Problem 2

Economies of Scale

Market Sizing & Estimation Overview

Market Sizing — Example 1

Market Sizing — Example 2

Market Sizing & Estimation — Recommendations

Growth Rate Analysis

Chart Reading 1

Chart Reading 2: Highly Recommended

Price Elasticity
 Summary & Conclusion

Summary & Conclusion
 Advanced Quant Topics

NPV 1 — Net Present Value Overview

NPV 2 — Perpetuities & NPV Examples

Calculating Doubling (& Halving) Time with Rule of 72

Compound Growth Calculations

NPV 3: Perpetuities with Growth

NPV 4: NPV Sensitivity to Growth & Discount Rates
 Advanced Quant Case Problems

Production Shifting (McKinsey Case)

Pipeline Analysis

Pipeline Analysis: Algebraic Solution
 Case Library

Investment Decision  Full Case

Competitive Pricing Response
FastMath Ace the Case
Ace the Quantitative Component of Case Interviews
Introduction
Hello! My name is Matthew Tambiah and I’m the creator of the FastMath Ace the Case Online Course. I’m a former McKinsey consultant and I designed this videobased online course specifically to teach you the quantitative and mental calculation skills you need to succeed in Management Consulting Case Interviews.
Many people are intimidated by math and quantitative problems given in Case Interviews as you can’t use calculators in the interview. In this online course, I will teach you the mentalcalculation methods I personally used to successfully navigate the McKinsey Case Interview process. I used similar methods throughout my academic career and they helped me gain entry to, and graduate from, both Harvard and MIT.
Overview
In the FastMath Ace the Case Online Course, I use ondemand video instruction to teach FastMath calculation methods designed specifically to simplify the type of calculations required in Case Interviews at elite Management Consulting firms like McKinsey, Bain and BCG. These FastMath calculation methods will make you faster and more efficient and reduce your calculation errors by drastically simplifying most Case Interview calculations (Case Calculations). I will also show you how to apply these FastMath calculation methods to the most common types of Case Interview quantitative problems, such as Market Sizing & Estimation problems and Breakeven Analysis problems.
The FastMath Ace the Case Online Course is different from other quantitative interviewpreparation resources because it uses ondemand video lessons to teach you how to do Case Calculations faster and more efficiently, whereas most other quantitative interviewprep resources simply provide practice problems and answers — without teaching methods to efficiently perform the calculations without a calculator. Furthermore, all the calculation methods in this course are designed for the types of calculations you will actually encounter in a Case Interview, and all the example problems are based on problems given in actual Case Interviews at elite Management Consulting firms, while many other resources use examples that don't effectively simulate actual Case Interview problems.
The FastMath Ace the Case Online Course will enable you to maximize your performance in Case Interviews, and is the recommended quantitative preparation resource for the consulting clubs at Wharton, Columbia Business School, London Business School and numerous other MBA programs. More than 5,000 candidates worldwide have used the FastMath Ace the Case Online Course to prepare for Management Consulting interviews. Discover why top MBA students love FastMath, and maximize your own interview performance by registering for the FastMath Ace the Case Online Course.
You can preview several lessons — see the blue links on the right.
Course Features
 7+ hours of ondemand video lessons
 10 full quantitative Case Interview problems and solution methods
 40+ lessons/modules
 Efficient calculation methods
 Comprehensive practice problems and solution methods
 Downloadable tables and reference files
 24month subscription
 30day moneyback guarantee
 Mobile responsive platform (iPad, iPhone and Android accessible)
 Quant techniques helpful for the McKinsey PST (e.g. accurate compound growth calculations)
 All calculation methods, examples and practice problems are based on real Case Interview calculations
Course Details
The FastMath Ace the Case Online Course has two components. In the first half of this course I will teach you a set of FastMath calculation methods, which will enable you to do multiplication, division, percentage and compound growth calculations faster and more efficiently without a calculator — as required in Case Interviews. In the second half of this course, I’ll show you how to apply the FastMath calculation methods to the most common types of quantitative problems given in case interviews, such as Market Sizing & Estimation problems, and Breakeven Analysis problems. I will illustrate the most efficient solution method for each problem type and show how to use the FastMath calculation methods to solve the problems quickly and efficiently. I will also highlight how to use the quantitative results to develop Case insights and recommendations. I’ll provide you with numerous full Case Interview example quant problems with detailed solution methods, and comprehensive practice problems and solution methods that reinforce the course material.
Mental Math Methods
Learn methods to improve speed and efficiency for the following calculation types:
 Multiplication and division
 Percentage calculations
 Fractions and decimal calculations
 Compound growth calculations
 NPV calculations
Quant Problems Types
The FastMath Ace the Case Online Course provides examples and solution methods for the most common types of quantitative problems given in Case Interviews, including:
 Market Sizing and Estimation problems
 Chart Reading
 Breakeven Analysis
 Economies of Scale
 Price Optimization
 Growth Rate Analysis
 Net Present Value (NPV) calculations
30day Moneyback Guarantee
If you're unhappy with this course for any reason, email me and I will give you a refund.
Articles on Math Skills in the Context of Case Interviews
 Math Skills Required in Case Interviews
 How to Prepare for the Quantitative Component of Case Interviews
 Why Management Consulting Firms Assess Math Skills
Real Case Calculations and Case Numbers
Before I created this course, I looked at numerous quantitative problems that top Management Consulting firms like McKinsey, Bain, BCG, Accenture and Deloitte had given to their candidates in Case Interviews. I then created the course content to teach people the most effective ways to solve the actual problem types elite Management Consulting firms were asking candidates to solve.
By looking at the actual calculations required in Case Interview, I also noticed that the specific numbers involved in the Case Calculations, which I will refer to as Case Numbers, had specific properties you could use to simplify the calculations — if you knew the proper calculation methods. The Case Numbers showed signs of being carefully chosen, and the calculation methods I teach in the FastMath Ace the Case Online Course are designed specifically for the actual calculations required in Case Interviews.
Case Numbers are usually “Round” numbers with a few significant digits, such as 300,000 or 4,000,000. Some people may be intimidated by having to do a calculation like (4,000,000 × 20,000) without a calculator. In this course, I’ll teach you efficient methods to manage the zeroes (see Multiplication Lesson), so that calculations like these will become easy. When Case Numbers have more than one significant digit, they usually have certain characteristics that can make calculations like multiplication and division much easier.
Example Case Calculation
You are told that a company sells a Product for $32 per unit and sells 25,000 units per year, and then you are asked to calculate the Revenue.These numbers are representative of actual Case Numbers, and you would need to do the calculation: ($32 × 25,000). You can execute this calculation by multiplying (32 × 25) and then writing the three zeroes from “25,000” at the end of this result. Here is a way to efficiently perform the calculation (32 × 25) using relevant characteristics of these Case Numbers.
First decompose 25 as: (25 = ¼ × 100). Then perform the calculation using this decomposition of 25.
32 × ¼ = 32 ÷ 4 = 8
8 × 100 = 800
Therefore (32 × 25 = 800). You can (and should) verify this with a calculator or pen and paper. This method works because (25 = ¼ × 100), and so (4 × 25 = 100); so, when you divide 32 by 4, the result is the “number of groups of 100.” In general, to multiply any number N by 25, you divide N by 4, and then multiply the result by 100. Now the answer to our original problem of ($32 × 25,000) is then $800,000.
Most multiplication and division calculations required in actual Case Interviews involve numbers like this for which there is a way to dramatically simplify the calculation. In the Fastmath Ace the Case online course, I’ll provide you with a comprehensive set of methods for multiplying and dividing with the Case Numbers you are most likely to encounter in actual Case Interviews.
Beware of “Imposter” Case Calculations and Case Numbers”
Many other quantitative Case Interview preparation resources have example calculations with Case Numbers you are highly unlikely to encounter in an actual Case Interview, such as multiplying by a number like 23,487 — or a number with five (or more, significant digits. Practicing calculations with numbers with many significant digits is not an effective way to prepare for Case interviews as these calculations are not representative of actual Case Numbers or Case Calculations. You will be practicing bruteforce mechanical calculation skills which you won’t need in Case Interviews, and won’t get experience looking for and finding methods to simplify calculations.
If you see example problems where you are multiplying or dividing by numbers with four or more significant digits, or adding numbers with five or more significant digits, this is a red flag indicating these calculations are likely “made up” and not representative of actual Case Numbers and Case Calculations. As a result, there are no longer efficient methods to perform the calculation — and practicing with these types of problems is not an effective way to prepare for actual Case Interviews.
All the calculation methods, example problems, and practice problems in the Fastmath Ace the Case Online Course are based on actual Case Calculations (and the specific Case Numbers involved) from leading management consulting firms like McKinsey, Bain, BCG, Accenture and Deloitte. Therefore, I believe the FastMath Ace the Case Online Course is the best quantitive Case Interview preparation resource because the material is based on what you will encounter in actual Case Interviews.
Testimonials
“Excellent material! This course definitely helped me land a job at McKinsey!”
McKinsey consultant and Columbia PhD graduate
“Quant used to be one of my weak areas regarding consulting interviews. After taking your course and practicing the methods, it’s now one of my strongest areas.”
Wharton MBA student
“A+ This course is an essential tool in your arsenal for acing the consulting interviews!”
MIT Master in Engineering and Management student
“The techniques and methods suggested are very useful and in most cases are exactly the same I use when I do computations in my head. If you want to improve your speed, you should take the course.”
McKinsey consultant and MIT Physics PhD graduate
“This course is essential material you must learn before your Case Interviews”
MIT Master in Finance student
Other Resources
Quant Selfdiagnostic Quiz
 Quant Selfdiagnostic Quiz
 Solutions for Quant Selfdiagnostic Quiz
Mental Math Exercises
FastMath Ace the Case Facebook Discussion Group
FastMath Ace the Case Facebook Page
About Me
Matthew Tambiah
Former McKinsey Consultant
 Bachelor's from Harvard with Highest Honors in Electrical and Computer Engineering
 MBA from MIT Sloan
My name is Matthew Tambiah and I am the creator of the FastMath Ace the Case Online Course. I have taught FastMath Ace the Case Workshops at Harvard Business School, Wharton, MIT, London Business School, INSEAD, Georgetown and numerous other leading universities. Thousands of candidates from around the world have used the FastMath Ace the Case Online Course to prepare for Case Interviews. My students have joined McKinsey, Bain, BCG, PwC, Accenture, Deloitte, Booze Allen, and other leading consulting firms. I have a Bachelor's degree from Harvard with Highest Honors in Electrical and Computer Engineering. Before I attended the MBA program at MIT, I worked at Akamai Technologies, a leading computer networking firm, in both Silicon Valley and Cambridge, Massachusetts, in sales engineering, product management and product marketing roles.
Math and science subjects always came naturally to me and I frequently helped friends with these subjects in high school, in college at Harvard, and in graduate school at MIT. I have received the following scores on math and science standardized tests
 Math SAT: 800/800
 GMAT: 99th
 Advanced Placement BC Calculus: 5/5
 Advanced Placement Physics C Mechanics: 5/5
 SAT Mathematics Level 2 Subject Test: 800/800 (formerly named the SAT Math II Achievement test)
I developed the concept for the FastMath Ace the Case Online Course when I was in business school at MIT. I was enrolled in the 2year MBA program at MIT, and I spent the summer between the first and second year working in the technology practice at McKinsey. When I returned to school in the fall of my second year, many classmates asked me to help them prepare for their Case Interviews because I had successfully navigated the process. I started giving people some of the Case Interview questions I received, and noticed that many people struggled with the quant problems — even people with strong math and science backgrounds. There were many Case Interview preparation resources, but I didn't think they did a good job helping people prepare for the quantitative component of Case Interviews, so I volunteered to host a workshop on quant skills for Case Interviews for MIT students through MIT Sloan Management Consulting Club. My classmates like the material and this was the inspiration for the current version of the FastMath Ace the Case Online Course.