Schedule mock interviews on the Meeting Board, join the latest community discussions in our Consulting Q&A and find like-minded Interview Partners to connect and practice with!
Back to overview

Any tips on how to calculate

I have problems getting a decent score in the hard section of the "percent" exercises in the Mental Math tool here on the site.

Any tips on how to solve this kind of complex operations?

4
4.5k
36
Be the first to answer!
Nobody has responded to this question yet.
Top answer
Deleted user
on Sep 18, 2018

Another little tip is to practice with multiplications, rather than divisions. It seems to be easier on the brain.

E.g. 30% of 7 is easier done this way:

1) 7 x 30 = 210

2) Divide by 100.

2
Deleted user
on Sep 17, 2018

Practice, practice, practice...

Also, there are some shortcuts I find useful:

  • 90% of X - just divide X by 10 and subtract from X. 
  • x% of 1xx - maybe easier to take (x% * 100) + (x% * xx)
  • 20 / 40 / 60 / 80% of 65 / 75 / 85: Take 20 / 40 ... % of 70 / 80 / 90 and subtract 1 / 2 / 3 / 4. So 40% of 65 = 40% of 70 - 2 = 28 - 2 = 26 
1
Vlad
Coach
on Sep 17, 2018
McKinsey / Accenture Alum / Got all BIG3 offers / Harvard Business School

Hi,

Simply learn the division table up to 1/11 (i.e. 5/6 = 83.3%). It will help you calculate any percentage problems

Best

Deleted
Coach
on Sep 18, 2018

All good tips below. Ultimately it comes down to personal preference. My tips for dealing with percentages (especially complex ones): think of everything in terms of divisions of 10 and 2 --> i.e. almost any percentage, you can reach by dividing your initial number by 10 or by 2

Example - 37.5% of 460:

- 30% =3*10% = 46*3= 138

- 5% = 23

- 2.5% = 11.5

37.5% = 138+23+11.5 =172.5

Hope this helps!

Alessandro

Similar Questions
Consulting
Mckinsey solve test in 3 weeks - how to organise?
on Nov 05, 2024
Global
2
2.7k
44
2 Answers
2.7k Views
Consulting
Why do I get the math part wrong everytime and how can i improve?
on Jan 22, 2025
South America
7
1.3k
23
7 Answers
1.3k Views
Consulting
How do I improve self confidence?
on May 28, 2025
Global
7
500+
21
7 Answers
500+ Views
Consulting
Mental Maths: Best way to do division?
on Jul 20, 2025
Global
6
100+
5
6 Answers
100+ Views