Division Hard

case math Math problem
New answer on Aug 10, 2022
4 Answers
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Anonymous A asked on Aug 08, 2022

Hi,

can someone share a few good tricks to easily beat Division Hard on PrepLounge and achieve > 20 points?

I practice a lot and would humbly consider myself not too bad at Math, but I just find it super difficult to reach above target.

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Emily
Expert
replied on Aug 10, 2022
Ex McKinsey EM & interviewer (5 yrs) USA & UK| Coached / interviewed 200 +|Free 15 min intro| Stanford MBA|Non-trad

What everyone has said here is right - you don't need to be a maths ninja! (Take it from someone who is more a maths snail). You do need though to be able to do basic maths - make sure you know how to divide really big numbers (what is a million divided by a thousand?); you know your times tables up to 12; and you know how to calculate percentages.

Sometimes though in the case interviews the firms are interested in whether you know where to ‘cut corners' (or 80/20) to get to the best possible answer in the most efficient amount of time (80% of the answer in 20% of the time). So if you're presented with a problem which requires really complex long division, is there an obvious way to round the numbers to make it easier and faster?  

And if you're really stuck just ask! I was expected to know the square root of 2 in an interview - I didn't so just asked - and got the offer :-) 

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Ashwin
Expert
Content Creator
replied on Aug 09, 2022
Ex Manager Bain and company | INSEAD

Hey there , 

A fundamental mistake that candidates make is they think they need to become a arithmetic ninja who can do fast case math to do well. In a case interview what is tested is your ability to conceptualise the quantitative analysis approach and to arrive at a reasonably accurate answer with minimal guidance . No interviewer is timing the speed with which candidate has done the math computation . Infact , in some cases I have seen speed negatively impact the candidate because in their rush to do fast math calculations they have failed to adequately describe the analysis approach to the interviewer .

It is important to have a general comfort with math but don’t lose sight of what is really being tested in the interview - Speed is definitely not a evaluation criteria

Thanks 

Ashwin 

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Sofia
Expert
replied on Aug 09, 2022
McKinsey San Francisco | Harvard graduate | 5+ years of coaching | DISCOUNTED SESSIONS Sep 2022 | Free 15 min intro call

Hello,

Agree with Ian here - it's great that you're serious about practicing math, but don't worry too much about getting a particular score on Division Hard. Focus on getting the math portion of a case correct and solving it quickly. If you are doing so consistently, you should be in good shape for (the math part of) a case interview.

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Ian
Expert
Content Creator
replied on Aug 09, 2022
MBB | 100% personal interview success rate (8/8) and 95% candidate success rate | Personalized interview prep

Hi there,

Remember that casing isn't a math competition…don't loose sight of the forests for the trees!

If you can complete most math in a case in a methodical, reasonably fast, and accurate way, then you're good! Don't worry about highscores - worry about case performance!

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Emily gave the best answer

Emily

Ex McKinsey EM & interviewer (5 yrs) USA & UK| Coached / interviewed 200 +|Free 15 min intro| Stanford MBA|Non-trad
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