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Improve my math

mental math
Recent activity on Oct 31, 2021
2 Answers
744 Views
Anonymous A asked on Oct 29, 2021

Hello there,

I have an interview with McKinsey in one moth and I really want to improve my mental math and was wondering if anyone can suggest any resources or Apps that I can use to improve mu mental math.

Thank you in advance  

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Ian
Expert
Content Creator
replied on Oct 29, 2021
#1 BCG coach | MBB | Tier 2 | Digital, Tech, Platinion | 100% personal success rate (8/8) | 95% candidate success rate
  1. 100% Recommend Rocket Blocks. It's exactly what you're looking for
  2. Online "Drills": https://www.preplounge.com/en/mental-math
  3. Math sheets (print these and do them on paper): Google Math Drills sheets
  4. In addition to that, you can ask other PrepLoungers to case you on math-heavy cases. You can also search for those case types here and work through them yourself.

Some key formulas/concepts:

  • Breakeven
  • NPV (with + without growth, perpituity + 1-2 years from now)
  • % Change
  • ROI
  • Margin
  • Markup
  • Inventory turnover

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Some great answers from a variety of angles have already been asked. Check these out!

Mental Math

https://www.preplounge.com/en/consulting-forum/mental-math-help-7962

Conceptual/Contextual Math

https://www.preplounge.com/en/consulting-forum/materials-for-practicing-conceptual-case-math-8016

Key Math Equations

https://www.preplounge.com/en/consulting-forum/math-equations-their-use-7934

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Agrim
Expert
Content Creator
replied on Oct 31, 2021
BCG Dubai Project Leader | Learn to think like a Consultant | Free personalised prep plan | 6+ years in Consulting

Along with the resources mentioned by Ian, I would like to say that key to mastering mental math is practice.

And not just any practice - you must practice “all the time”.

  • At the grocery store? Practice mental addition and multiplication while you put items in your basket - to estimate the final amount.
  • Watching TV? Switch to business channels and try to calculate % change in share prices based on $ value (or vice versa)
  • Doing a math drill? Create a variation and solve it as well

ANOTHER aspect that is crucial in building mental math capabilities is “VISUALIZATION”. The best mental math masters literally create numbers virtually in front of their eyes. They perform the exact “on-paper” math, but in mid-air. Try to get that flow going.

FINALLY, the last aspect (related to practice) is to develop muscle memory. Certain multiplications, fractions, percentages should start coming as a reflex. This will help you in saving time and calculation steps.

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