McKinsey final round, math calculation errors

Question

Case 1 - I got the approach to the case correctly up front. But then I made two calculation mistakes. It took me a bit on the first one to get the correct answer. On the second one, the partner just said that it was close enough so to move on. But the math errors threw me a bit off so I had to be redirected a bit after that - I started to take a long approach on the second part but then realized there was a shortcut and told the interviewer of the short cut and finished the case.

Case 2 - I did the math really well. The partner even had me skip half the math saying that I could clearly do the math and she has no issues on that front so she said let's just move on. I did really well on this case.

Case 3 - had no math at all. It was unconventional but I held my ground.

Since the third case had no math, I worry that my math can't be assessed accurately. How fatal is the this????

Answer 1

Hi Anonymous,

If everything else apart from marth was clearly above par in your case interview, this single mistake alone won't throw you out of the process. It's one data point of many - so don't worry too much about that!

Especially if you did the math portion well in the 2nd interview - they got the idea that you are generally comfortable with numbers.

And: you also don't know the benchmark level from other candidates and what the interviewer did expect (obviously no math mistakes, that's clear, but still there is a certain expectation level from the big picture which you can't know or judge yourself).

Hope that helps - if so, please be so kind to give it a thumbs-up with the green upvote button below!

Robert

Answer 2

A math hick-up in one case doesn't through you off. The cases are evaluated holistically and a low math score in one does not mean anything. If multiple things where not great, then of course the math is one piece in the puzzle that leads to your rejection.

Overall it's extremely difficult to judge your own performance - even more so on dimensions like your overall structure, your creativity and how you're driving the case. So speculating on how it went is pretty much pointless.

To give an example: I was convinced I completely bombed my 4th interview at Bain because I just misread the interviewer. Turns out the case was spot on and I got the offer.

Answer 3

No interview is ever perfect. Also very very few people are good judges of their performance. It could matter or it could be overlooked depending on factors like your structuring, PEI and how the others performed on the day

All the best to you

Udayan

Answer 4

Certainly not fatal. For a few reasons:

1) You say you did really well on the 2nd case, so they might be willing to overlook the mistakes on the first one

2) You passed the first round. Especially if you did well on math there, there will be a lot of evidence that you can do it, just hit a rough spot.

I wouldn't worry about it. Let us know how it turned out for you!

Answer 5

Hi there,

Unfortunately no one can predict the outcome of this interview round. Making one math mistake in 1/3 cases should not be fatal, but you never know!!!

In all the cases, you cannot change much now, so try to relax and disconnect a bit until you get the call from the HR or one of your interviewers next week!

All the best,

Mehdi

Answer 6

You should be fine. There is an expected hygiene level but strong maths alone doesn't get you an offer where final round interviewers sometimes do this. Assuming other sections of the case and PEI went well, there should be enough data points for your interviewers to make a final decision.

Fingers crossed!

Answer 7

Hi there,

This actually sounds perfectly fine to me.

While, of course, I can't say whether you got the job or not, it doesn't seem like this math error would knock you out.

The Partners talk to each other afterwards! Once would note that you messed up on the math and the other would note that you nailed it. They will likely decide that you probably just got a bit rattled and would move on. If this was indeed the only issue, then you are fine! (Note: We are not good at evaluated our own success, so I have to emphasize the "IF")

Answer 8

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