Case math can absolutely be a meaningful weakness, but repeated interview failures are usually worth diagnosing more broadly. Slow or shaky math can affect much more than one calculation because it interrupts the pace of the case and can lower the interviewer’s confidence in your overall problem solving.

At the same time, candidates often notice the most obvious mistake and miss quieter issues such as weak synthesis, generic structure, or answers that are technically correct but not very decisive. If you are repeatedly reaching interviews, your profile is doing its job; the next step is to get more precise about the performance gap.

I would review several recent mocks with strong partners and ask them to score you independently on structure, math, insight, communication, and recommendation. If math is consistently the only clear weakness, then you have a focused problem to solve.

Do not just add more random cases. Isolate the weak skill, train it directly, then test whether the improvement actually shows up in full interviews.

Math can hurt the whole vibe of the case if the interviewer has to wait for every calc.

Are you getting the math wrong or mostly just slow? Those would worry me differently.

I thought math was my issue too and later realized my synthesis was actually worse.

Get someone strong to score a few mocks. Your own post-interview diagnosis can be pretty biased.