Get Active in Our Amazing Community of Over 448,000 Peers!

Schedule mock interviews on the Meeting Board, join the latest community discussions in our Consulting Q&A and find like-minded Case Partners to connect and practice with!

How does the Consulting Q&A work?

Anyone can ask a question
Anyone can write an answer
Upvotes let answers rise to the top
What would you like to ask or discuss?

Mental Math ressources

case math fast math math logic
Most recent answer on Sep 01, 2023
The best answer (on Sep 01, 2023) is from:
Clara
Expert
McKinsey | Awarded professor at Master in Management @ IE | MBA at MIT |+180 students coached | Integrated FIT Guide aut
Clara
Expert
gave the best answer on Sep 01, 2023
McKinsey | Awarded professor at Master in Management @ IE | MBA at MIT |+180 students coached | Integrated FIT Guide aut
Hello! Precisely for the high amount of questions (1) asked by my coachees and students and (2) present in this Q&A, I created the “Economic and Financial concepts for MBB interviews”, recently published in PrepLoun ... (read entire answer)
5
Answers
2.4 k
Views
7
Total Upvotes
on Sep 01, 2023 on Sep 01, 2023
Last Activity

Mental math competition

fast math
Most recent answer on Aug 31, 2023
The best answer (on Jun 21, 2023) is from:
Cristian
Expert
#1 rated MBB & McKinsey Coach
Cristian
Expert
gave the best answer on Jun 21, 2023
#1 rated MBB & McKinsey Coach
Hi there,  Yes, you can use this: https://arithmetic.zetamac.com/ It's basic and straight to the point.  However - without knowing where you are in the process - most candidates need to work on their technique for appro ... (read entire answer)
5
Answers
458
Views
23
Total Upvotes
on Aug 31, 2023 on Aug 31, 2023
Last Activity

Request for a division table for percentage conversions

case math Division fast math Math tool
Most recent answer on Aug 31, 2023
Anonymous gave the best answer on Dec 08, 2018
Hey there, I made the following quickly on Excel. However, I wouldn't advise you to try memorise the whole thing, as it's a) a lot to try remember and b) doesn't have that much value. Rather, memorise the first column ... (read entire answer)
3
Answers
5.7 k
Views
5
Total Upvotes
on Aug 31, 2023 on Aug 31, 2023
Last Activity

Math for case interviews

Case Interview fast math math
Most recent answer on Jul 27, 2023
The best answer (on Feb 26, 2020) is from:
Vlad
Expert
McKinsey / Accenture Alum / Got all BIG3 offers / Harvard Business School
Vlad
Expert
gave the best answer on Feb 26, 2020
McKinsey / Accenture Alum / Got all BIG3 offers / Harvard Business School
Hi, I recommend downloading all casebooks available online and check the math problems. You'll have a good list. Here are some of them to keep in mind: Interest rates calculations Compound margin NPV using the ... (read entire answer)
7
Answers
26.1 k
Views
25
Total Upvotes
on Jul 27, 2023 on Jul 27, 2023
Last Activity

Preparing from the basics

1stround BCG Case Interview BCG McKinsey and Bain fast math Framework hypothesis mental math numerical Structure
Most recent answer on Mar 10, 2023
The best answer (on Mar 08, 2023) is from:
Francesco
Expert
#1 Coach for Sessions (4.000+) | 1.500+ 5-Star Reviews | Proven Success (➡ InterviewOffers.com) | Ex BCG | 10Y+ Coaching
Francesco
Expert
gave the best answer on Mar 08, 2023
#1 Coach for Sessions (4.000+) | 1.500+ 5-Star Reviews | Proven Success (➡ InterviewOffers.com) | Ex BCG | 10Y+ Coaching
Hi there, Q: I am looking for advice on how to prepare.  In terms of general preparation, I would recommend the following: Define a calendar for your preparation. Identify how many hours you have before your interview a ... (read entire answer)
5
Answers
657
Views
61
Total Upvotes
on Mar 10, 2023 on Mar 10, 2023
Last Activity

Is getting good at mental math important after job offer

fast math Math problem Mental Maths
Most recent answer on Nov 25, 2022
The best answer (on Nov 23, 2022) is from:
Florian
Expert
Highest-rated McKinsey coach (ratings, offers, sessions) | 500+ offers | Author of The 1% & Consulting Career Secrets
Florian
Expert
gave the best answer on Nov 23, 2022
Highest-rated McKinsey coach (ratings, offers, sessions) | 500+ offers | Author of The 1% & Consulting Career Secrets
Hi there, I would say it is very helpful as it allows you to quickly calculate, estimate, or sanity-check numbers in client meetings or team problem solving sessions. You would not always have the time to pull out your ... (read entire answer)
6
Answers
788
Views
27
Total Upvotes
on Nov 25, 2022 on Nov 25, 2022
Last Activity

Math: word problems exercises

Case Interview case interview preparation case math fast math math Math problem mental math Word problems
Question edited on Sep 05, 2021
The best answer (on Aug 08, 2018) is from:
Vlad
Expert
McKinsey / Accenture Alum / Got all BIG3 offers / Harvard Business School
Vlad
Expert
gave the best answer on Aug 08, 2018
McKinsey / Accenture Alum / Got all BIG3 offers / Harvard Business School
Hi, Something that helped my candidates - download ALL casebooks available online and go through the math problems in the cases. They will give a good sense of required business terminology. Then you can google what y ... (read entire answer)
4
Answers
9.1 k
Views
5
Total Upvotes
on Sep 05, 2021 on Sep 05, 2021
Last Activity

Best resources for math improvement? (for a complete number novice!)

fast math math mental math Quantitative skills
Recent activity on Sep 05, 2021
The best answer (on Aug 22, 2019) is from:
Vlad
Expert
McKinsey / Accenture Alum / Got all BIG3 offers / Harvard Business School
Vlad
Expert
gave the best answer on Aug 22, 2019
McKinsey / Accenture Alum / Got all BIG3 offers / Harvard Business School
Hi, Basically, you need to develop 3 calculation skills: 1) Learn how to multiply double-digit numbers (https://www.youtube.com/watch?v=6ndkkPZYJHo). 2) Learn how to work with zeros. Best way - always use 10^power ... (read entire answer)
5
Answers
3.3 k
Views
9
Total Upvotes
on Sep 05, 2021 on Sep 05, 2021
Last Activity

Is quick mental math a skill that can be learned?

fast math
Question edited on Sep 05, 2021
The best answer (on Oct 28, 2019) is from:
Francesco
Expert
#1 Coach for Sessions (4.000+) | 1.500+ 5-Star Reviews | Proven Success (➡ InterviewOffers.com) | Ex BCG | 10Y+ Coaching
Francesco
Expert
gave the best answer on Oct 28, 2019
#1 Coach for Sessions (4.000+) | 1.500+ 5-Star Reviews | Proven Success (➡ InterviewOffers.com) | Ex BCG | 10Y+ Coaching
Hi Anonymous, it seems your problem is not the math itself, but the math under pressure. This is a very common problem for many candidates. The majority of the people are actually fine with math when there is no pre ... (read entire answer)
8
Answers
3.6 k
Views
37
Total Upvotes
on Sep 05, 2021 on Sep 05, 2021
Last Activity

Moltiplications/divisions with 6+ digits numbers, estimation math_Tricks

Case Maths estimation fast math GMAT MathSkills IB Guessestimation Math problem
Most recent answer on Nov 16, 2020
The best answer (on Jun 16, 2020) is from:
Francesco
Expert
#1 Coach for Sessions (4.000+) | 1.500+ 5-Star Reviews | Proven Success (➡ InterviewOffers.com) | Ex BCG | 10Y+ Coaching
Francesco
Expert
gave the best answer on Jun 16, 2020
#1 Coach for Sessions (4.000+) | 1.500+ 5-Star Reviews | Proven Success (➡ InterviewOffers.com) | Ex BCG | 10Y+ Coaching
Hi Anonymous, in general, the main issues with big numbers is forgetting zeros during operations. Potential tips to deal with big numbers are the following: Use correctly 10^ powers in your math computation. For e ... (read entire answer)
4
Answers
2.4 k
Views
2
Total Upvotes
on Nov 16, 2020 on Nov 16, 2020
Last Activity

Feeling stuck at Case Practice

case math case math' Case Maths case structure Case structure and frameworks Case Structuring Consutingmath fast math GMAT MathSkills IB Structure
Most recent answer on Oct 26, 2020
The best answer (on Oct 20, 2020) is from:
Adi
Expert
Accenture, Deloitte | Precision Case Prep | Experienced Interviewer & Career Coach | 15 years professional experience
Adi
Expert
gave the best answer on Oct 20, 2020
Accenture, Deloitte | Precision Case Prep | Experienced Interviewer & Career Coach | 15 years professional experience
Hi there, Two tips : 1. Practice, practice, and just dont give up. Give yourself time & celebrate little successes. Take a break for couple of days here and there and do something fun/creative to unclock the tra ... (read entire answer)
6
Answers
1.5 k
Views
30
Total Upvotes
on Oct 26, 2020 on Oct 26, 2020
Last Activity

Mental Math Help!

Case Timing fast math mental math Mental Maths
Recent activity on Sep 24, 2020
The best answer (on Sep 24, 2020) is from:
Ken
Expert
Ex-McKinsey final round interviewer | Executive Coach
Ken
Expert
gave the best answer on Sep 24, 2020
Ex-McKinsey final round interviewer | Executive Coach
When I was a candidate myself, I made a stupid math mistake (double counting) for my final round interview with a senior partner. Fortunately, it didn't lead to a rejection but I was asked to come back for an additional ... (read entire answer)
4
Answers
1.9 k
Views
56
Total Upvotes
on Sep 24, 2020 on Sep 24, 2020
Last Activity

Mental math app for practising fractions/percentages

case math fast math fraction math mental math percentage
Recent activity on Aug 08, 2020
The best answer (on Apr 13, 2020) is from:
Luca
Expert
BCG |NASA | SDA Bocconi & Cattolica partner | GMAT expert 780/800 score | 200+ students coached
Luca
Expert
gave the best answer on Apr 13, 2020
BCG |NASA | SDA Bocconi & Cattolica partner | GMAT expert 780/800 score | 200+ students coached
Hello Richard, Thanks for sharing! Actually I have many candidates that struggle with mental math, I will take a look to your app. Best, Luca
7
Answers
6.1 k
Views
33
Total Upvotes
on Aug 08, 2020 on Aug 08, 2020
Last Activity

Division techniques

case math Division fast math Math problem math test mental math
Most recent answer on Jul 08, 2020
The best answer (on Feb 19, 2018) is from:
Vlad
Expert
McKinsey / Accenture Alum / Got all BIG3 offers / Harvard Business School
Vlad
Expert
gave the best answer on Feb 19, 2018
McKinsey / Accenture Alum / Got all BIG3 offers / Harvard Business School
Hi, There are two techniques that you can use: 1) Learn how to work with zeros. Best way - always use 10^power instead of zeros Example: 300x9000 = 3*10ˆ2 x 9*10ˆ3=3x9*10ˆ(2+3)=27*10ˆ5 Handwritten it looks no ... (read entire answer)
6
Answers
11.9 k
Views
17
Total Upvotes
on Jul 08, 2020 on Jul 08, 2020
Last Activity

Math tricks for small decimal numbers

fast math Math problem
Recent activity on Nov 09, 2018
Anonymous A gave the best answer on Sep 07, 2017
Hi Jana, It won't work where you have really ugly numbers but one trick to keep in mind is the 'invert and multiply'. So to use your case: 0.024/0.08 = (0.024/1) / (4/5) = 0.024 * 5 / 4 ... (read entire answer)
5
Answers
6.6 k
Views
14
Total Upvotes
on Nov 09, 2018 on Nov 09, 2018
Last Activity

How to quickly calculate and analyze market share tables?

Exercise fast math Logic Math
Recent activity on Sep 25, 2018
Anonymous gave the best answer on Sep 25, 2018
Not sure whether I get the question... So BYB has 38% $-marketshare and 34%-unit share, then their $-share is overindexed by (38/34 = 1.12 (approx.)). So if every bus costs 150k (6 bln / 40 k), then their busses cost ... (read entire answer)
1
Answer
3.2 k
Views
1
Total Upvotes
on Sep 25, 2018 on Sep 25, 2018
Last Activity

Compound Annual Growth Rate McKinsey PST Questions

CAGR fast math Math tool McKinsey McKinsey PST
Question edited on Jan 28, 2018
The best answer (on Dec 30, 2017) is from:
Levente
50+ live cases, BCG 1st round on 18th of June
Levente gave the best answer on Dec 30, 2017
50+ live cases, BCG 1st round on 18th of June
Hi, whenever you are required to solve a compound interest problem you can go with two different logic: 1. When you want to know how much will value X will be in Y years given Z% growth each year: 1.1. Logic: You ... (read entire answer)
2
Answers
10.7 k
Views
19
Total Upvotes
on Jan 28, 2018 on Jan 28, 2018
Last Activity
17 results

Consulting Q&A – Ask Questions about Your Career

In this overview, you will find all the questions asked so far by the PrepLounge community. Anyone can ask questions and write answers. Our coaches are also happy to share their expertise. If you like an answer, give it an upvote so that it rises to the top. Here you can also find our guidelines and FAQs for the Consulting Q&A.

How likely are you to recommend us to a friend or fellow student?
0
1
2
3
4
5
6
7
8
9
10
0 = Not likely
10 = Very likely