Does mathematical accuracy matter while solving cases in an interview? How do I enable myself to do faster calculations?

Hi there,

I would be happy to share my thoughts on your questions:

• First of all, yes, mathematical accuracy - even if not to the 4th and 5th decimal - is crucial in case interviews because it reflects your analytical skills.
• Moreover, I would advise you to practice mental math using tools like the Mental Math Tool to improve calculation speed and accuracy.

You can find more on this topic here: Speed reading techniques.

If you would like a more detailed discussion on how to best prepare for your upcoming interviews, please don't hesitate to contact me directly.

Best,

Hagen

Hi,

Here's my take on your questions:

1. Does mathematical accuracy matter while solving cases in an interview

• Yes, accuracy matters, but with a caveat
• Interviewers are not looking for decimal accurate calculations, but instead proficiency with numbers including the basic functions (+ - / *) and orders of magnitude
• You are allowed to round smartly and perform calculations

2. How do I enable myself to do faster calculations?

• Practice, practice, practice. Proficiency with mathematical calculations can be improved through rote practice
• However, please note that what is more important is really the quantitative thinking and logic - if you can calculate at lightning speed but your logic is wrong, you aren't going to do well :)

All the best!

Mathematical accuracy does matter in case interviews, but it’s more important to make reasonable estimations rather than getting bogged down in precise numbers. Interviewers are looking for your problem-solving approach and logical thinking rather than perfect calculations. To enable faster calculations, practice mental math techniques such as rounding, using approximations, and breaking complex calculations into simpler steps. Regularly practicing with case studies and using tools like a “brain calculator” (shortcuts for common calculations) will also help you build speed and confidence.

Not really. I've passed candidates who have made multiple numerical errors. Contrary to belief, making a math mistake is not a death sentence. The key is 1) recovering quickly 2) spotting the mistake yourself and calling it out.

Enabling yourself to do faster calculations come from dedicated practice just like everything else. Go through several case books and run through the quant section - Verbalize it, and do it quickly. More importantly, speed of calcs isnt the key deciding factor for a go/no-go decision anyway

Great points have been made so far! Just to add:

• Mathematical Accuracy: Getting the math right is important, but what's crucial is your approach. Always outline your formula or method first—this shows your thought process and opens up discussion with the interviewer, which is key.
• Estimation and Rounding: Smart rounding and estimation can be very effective. The goal isn’t always to be exact but to be directionally correct. Make sure your assumptions are sound and can be clearly explained.
• Practice with Purpose: While tools like PrepLounge are useful for sharpening your math skills, it’s essential to practice within full case contexts. This helps you integrate structuring and estimation, leading to more well-rounded answers.

Best of luck with your preparation!

Hi there,

Not in the most direct sense but in the way that you

• reach an outcome swiftly, directionally correct
• correctly calculate using the approach and numbers you have chosen (rounded, simplified, etc.). For instance, if you choose to round your numbers to make the calculations easier you should then reach the correct outcome using those numbers. While technically you are not fully accurate due to the rounding, you still perform the calculations correctly while also demonstrating that you feel comfortable with handling large numbers
• can come up with a correct interpretation of the result

Cheers,

Florian