Mental Math Practice: LOMS vs. PrepLounge

LOMS mental math preplounge
New answer on Aug 31, 2020
5 Answers
2.2 k Views
Alexander asked on Dec 13, 2018

Hello everyone,

When talking about Mental Math, the tool that comes with the LOMS program is frequently recommended. How does this tool differ from the one offered by PrepLounge? I've been using the latter extensively - does it leave any gaps that I should cover via LOMS?

Looking forward to hearing back! Thanks,


Overview of answers

  • Upvotes
  • Date ascending
  • Date descending
Best answer
replied on Dec 13, 2018
Ex-MBB, Experienced Hire; I will teach you not only the how, but also the why of case interviews

Are you talking about I often recommend that specific tool, since I used it myself to great effect. It will rank you by accurracy and speed against other applicants. I do not know that it is exhaustive however.

PrepLounge didn't exist when I was preparing. All the tools & materials that I've seen here were of great quality, so I will hypothesize that the math tool is as well. That other website is free however, so no downside in checking it out as well anyway

Was this answer helpful?
Alexander on Dec 13, 2018

Thanks for the feedback! I did indeed mean - sorry about the confusion I caused. The two tools do indeed seem very similar, and I don't think that one is better than the other.

Content Creator
replied on Aug 31, 2020
McKinsey | MBA professor for consulting interviews
Was this answer helpful?
Anonymous replied on Dec 14, 2018

I can say they are essentially equivalent, and it is basically up to personal preference.

What I would also say is that you shouldn't overly worry about the percentiles that LOMS gives you. You can do perfectly fine without being even close to the top percentiles. Just make sure you can do math correctly, and don't be afraid to use paper in the interview to do the math (no need to do it in your head).

Was this answer helpful?
Content Creator
replied on Dec 13, 2018
McKinsey / Accenture Alum / Got all BIG3 offers / Harvard Business School


Any tool is good if you train the main skills:

  • Multiplication of the double digits
  • Division
  • Calculating with zeros

I personally use Mimir Math for iOs


Was this answer helpful?
Alexander on Dec 13, 2018

Thank you! I should be good then. I'll also check out Mimir Math.

Anonymous replied on Aug 28, 2020

Dear Alexander!

I agree with other coaches. When we talk about mental math, I can also advise you on an app called 'Case Math' on the iOS store to practice mental math fractions and percentages for your case interviews (https://apps

There are basically two reasons to do that:

1) Fractions are involved in many calcs: market sizing, margins, market share, etc.

2) Fractions are typically harder and less practiced than other operations - addition, subtraction & multiplication

If you need some help with your application, just drop me a line.



Was this answer helpful?
Guennael gave the best answer


Ex-MBB, Experienced Hire; I will teach you not only the how, but also the why of case interviews
Q&A Upvotes
171 Reviews