Why am I pretty great at Maths in Cases, but terrible at GMAT questions?

Hi there,

This is actually a super common experience — and you’re definitely not alone in feeling this way! I also had the GMAT test and I know exactly what you mean.

Case interview math and GMAT/PST-style math test different skill sets, even if they look similar on the surface. Here’s why you might be doing well in one and struggling in the other:
    1.    Case Math Is Contextual and Conceptual
In cases, math is typically tied to a business scenario. You’re not just crunching numbers — you’re applying logic and breaking problems down step by step. Even when calculations are tricky, your thinking is supported by a real-world framework, which helps you stay structured and focused.
    2.    GMAT/PST Math Is Abstract and Timed
GMAT questions (especially Data Sufficiency) and BCG’s PST are more abstract. They require quick pattern recognition, shortcuts, and number sense under tight time pressure. Unlike in cases, you don’t get partial credit for a good structure — it’s binary: right or wrong. That alone can make it feel more stressful and technical.
    3.    Mental Models vs. Test Strategy
In casing, you get to externalize your thinking — write down steps, sanity-check assumptions, and talk through logic. With GMAT/PST, you’re on your own, solving quickly and silently. If you haven’t trained specifically for these formats, even someone with strong math instincts can feel tripped up.

Tips to bridge the gap:
    •    Practice GMAT/PST questions in short sprints to build speed and stamina.
    •    Focus on recognizing question types — pattern recognition matters more than deep calculation.
    •    Try verbalizing your reasoning in GMAT practice like you would in a case, it can actually help reframe the problem.
    •    Don’t let it shake your confidence — being strong in case math is the skill that matters more for interviews.

You’ve got the core thinking nailed — it’s just a matter of adapting to a different test format. Keep at it, and you’ll find your rhythm.

Let me know if you need further help!

Best,

Evelina

Hi there,

Q: Why is it that when I do GMAT maths or BCG PSTs, I tend to perform terribly and take way too long? 

It might be for a number of reasons; possible ones are:

1. You suffer from time pressure (it is different to solve one math question with a human versus solving 20-30 questions with only 2 minutes for each, you against a timer)
2. You struggle to absorb written information compared to verbal ones
3. You are not used to these types of questions and simply need more practice

If you have done limited practice, this could be normal – you might just need to do more drills. If you have done significant practice (say three different PSTs) without any improvement, it is likely that you have issues with certain questions or methodologies that need to be addressed (in this case, we would need more information to know which they are).

Hope this helps,
Francesco

That's interesting. 

It might mean that you're better at doing maths when it's presented within a business context. Actually, this is good news and a strength once you join a consulting firm. 

Try not to obsess too much about it. The reality is that with these math drills, annoying or boring as they might sometimes be, the more you do, the better you get. So put in the work and the result will show.

You might also find this useful:

• Cheatsheet: The Must-Know Consulting Terms for Interviews

Best,
Cristian

Hello there,

As you have said, the format is different. Case interview allows you to have more context, time and you can perform a math exercise breaking it down in several micro tasks, while GMAT/PST are straightforward calculations with very limited time to complete them.

Don’t try to compare both, because they are different. You will have to learn how to tackle GMAT questions in a specific way. E-gmat has great resources, some of them free of charge.

Good luck! Put in the hard work and you’ll surely get the results you’re seeking!

Best,

Mari

Hi there,

What you are describing is more common than you think because it's two very different tasks.

Why are you struggling (potentially)?

• Different mental modes: Case interviews reward open-ended, structured thinking, where you have to go through 1-2 math problems during the 25-minute-long process, embedded into a proper context and many other tasks to work on. GMAT/PST math is rigid, more time-pressured, and punishes hesitation (also there is just much more of it back-to-back). You’re switching from synthesizer to calculator.
• Precision vs. progress: In cases, estimations and rough math and directionally correct results are acceptable or even desirable. In GMAT/PST, precision matters much more.
• Lack of pattern recognition: GMAT/PST questions often follow repeatable formats (e.g. work-rate, ratios, overlapping sets). If you're not trained on recognizing and snapping to the right method quickly, you'll burn time re-deriving logic.

What can you do about it?

1. Drill pattern recognition: Build a mental toolbox for common GMAT/PST question types and rehearse them under time pressure.
2. Train time-cutting habits: Write less, think in shortcuts, and avoid checking your work obsessively; accuracy must be second nature.
3. Isolate and train GMAT/PST mode: Don’t mix it with case prep. Treat it like sport-specific conditioning. You wouldn’t train for sprinting with marathon form.

All the best,

Florian

Practice, practice, and more practice—with focused drills.

Start by ignoring the clock and focus on mastering the foundations first.

Speed and accuracy will come naturally as you build confidence.

There are plenty of great free GMAT resources available online—just do a quick Google search to get started.

Best,

Alberto

—

Explore my latest case inspired by a real MBB interview: TitanTrail - Operations Outsourcing

First off, well done on being strong at math during case interviews — that’s already a great sign of analytical thinking under pressure.

What you’re experiencing is very common. Case math is contextual and applied, often tied to a business story. It rewards structured thinking and estimation, which it sounds like you’re naturally good at. In contrast, GMAT quant and PST questions are abstract, time-pressured, and often test pattern recognition or technical tricks, which can feel disconnected and mechanical.

A few things that might help:

• Don’t confuse GMAT difficulty with real consulting skills — firms care more about your reasoning, not whether you spot a geometry shortcut
• Focus on timed drills and mental math shortcuts to improve pacing — it’s a muscle you can train
• Remember your strength lies in business logic, which is far more valuable in actual interviews

It’s totally normal to struggle with test-style quant while excelling in live cases — you're not alone in this. Stay focused on what matters most, and keep going. You’re on the right track.