So I am good on mental math--not a genius by any means but good enough to pass the screening "this guy has no problem with numbers", I was told that in a few interviews so I feel comfortable with that but could definitely improve speed.

My issue is during the stress of an interview figuring out CONCEPTUALLY how to do the math sometimes. Hopefully you know what I mean, you're given a bunch of information and it's not really clear HOW to solve for X immediately, even though once you set it up the calculations are quite rudimentary.

I failed two MBB interviews last year based on screwing this up alone, then another MBB first round I got told I was "good at math" because the cases were fairly simple in setting up the math just doing a bunch of number crunching.

An example I mean is the "Mexico city taxi" case from an old casebook. This one wrecks most people because you're given a ton of numbers without a clear path to get to the answer see it here to see what I mean, it's the first case: https://masterthecase.com/case-interview-casebook-wharton-2009/

This year I'm trying to hone in on fixing my problem by asking my practice casers to give me the hardest math cases but I'm afraid it's not enough. Are there any resources out there to practice the conceptual part of case math, maybe hard "word problems" or something vs. "find profitability from a bunch of big numbers" which isn't so helpful for me.

I know that If I can fix this problem I can crush interviews because all my other skills are great--on easier math cases I've been told by MBB folks that I'm well above average, but if I get a case with tough math I bomb it--I know some of it is nerves but I want to remove the volatility in my casing as much as possible. Thanks for any advice!