I have been on 4 cases with 2 other newbies and in all cases, we struggled a little bit (or more) with the calculations.
E.g. How much is 43 of 90 in % (yes not super complicated but we need to get used to it. Would it have been ok to suggest in a real interview to calculate with 1EUR instead of 90Cents?
So, when is simplifying ok or when is simplifying def not ok?
Thanks!
(editiert)
Hi Anonymous,
first of all, let me state that one result of proper case interview preparation will be that this question will become completely irrelevant to you. ALL calculations in Consulting case interviews are utterly simple! You just need to internalize these important points and act accordingly:
1. You NEVER do calculations in your head! Interviewers are not at all interested in your ability to do calculus in your head! The only thing that counts is that you can be trusted to consistently come up with the correct result.
2. Don’t worry about speed! Again, the interviewer wants to see you come to the correct result in a very secure way - NOT in a speedy way
3. As a consequence of the above, concentrate on practicing written calculations of all sorts. All 4 operators (+, -, x, /). Thereby you will quickly get to the level where it becomes completely irrelevant whether you solve for 43% of 90 or out of 100.
If you still want to get a rule of thumb on rounding, I think it is permissible if well below 10%. In your example 100 is clearly more than 10% above 90, so it seems like a stretch to me.
Alkways ask for permission. If it's not given then proceed with long form calculation. If it's given make sure you do not do approximations of approximations (e.g. 43/90, ok if they let you to approximate to 4/9 but then is not acceptable to approximate that to 4/10).
Hope this helps,
Andrea
Hi Anonymous,
in general terms:
It’s important that in both cases – thus also in a market sizing - you ask the interviewer if it is indeed ok to approximate the calculation. If you just round without asking, it could be perceived as a mistake in your math, or at the bare minimum a mistake in communication since you did not align upfront.
Best,
Francesco
Hi,
I don't necessarily agree with the previous advice - most of the calculations you can do in your head pretty fast:
Best
Super Sidi, thanks à lot for your help and quick response!
