Cookie and Privacy Settings

This website uses cookies to enable essential functions like the user login and sessions. We also use cookies and third-party tools to improve your surfing experience on preplounge.com. You can choose to activate only essential cookies or all cookies. You can always change your preference in the cookie and privacy settings. This link can also be found in the footer of the site. If you need more information, please visit our privacy policy.

Data processing in the USA: By clicking on "I accept", you also consent, in accordance with article 49 paragraph 1 sentence 1 lit. GDPR, to your data being processed in the USA (by Google LLC, Facebook Inc., LinkedIn Inc., Stripe, Paypal).

Manage settings individually I accept
4

Mental Math ressources

Hello,

Do you have any reliable (free online or book) resources to develop mental math techniques? I need a methodology and a way to progress.

Thanks in advance !

Hello,

Do you have any reliable (free online or book) resources to develop mental math techniques? I need a methodology and a way to progress.

Thanks in advance !

4 answers

  • Upvotes
  • Date ascending
  • Date descending
Best Answer

Hi A,

Here is math app for practicing math fractions and percentages from one of PL participant https://apps.apple.com/us/app/case-math/id1507653375?mt=8&ign-mpt=uo%3D4

Also, here is a tool provided by PrepLounge (https://www.preplounge.com/en/mental-math.php

And you can use Victor Cheng’s math tool and Magoosh's mental maths app, Mental math cards challenge app etc

Best,

André

Hi A,

Here is math app for practicing math fractions and percentages from one of PL participant https://apps.apple.com/us/app/case-math/id1507653375?mt=8&ign-mpt=uo%3D4

Also, here is a tool provided by PrepLounge (https://www.preplounge.com/en/mental-math.php

And you can use Victor Cheng’s math tool and Magoosh's mental maths app, Mental math cards challenge app etc

Best,

André

Book a coaching with Vlad

97% Recommendation Rate

407 Meetings

11,415 Q&A Upvotes

USD 239 / Coaching

Hi,

Basically, you need to develop 3 calculation skills:

1) Learn how to multiply double digit numbers (https://www.youtube.com/watch?v=6ndkkPZYJHo).

2) Learn how to work with zeros. Best way - always use 10^power instead of zeros

Example:

300x9000 = 3*10ˆ2 x 9*10ˆ3=3x9*10ˆ(2+3)=27*10ˆ5

Handwritten it looks not that complicated. If you get used to writing all the numbers that way, you will never loose zeros and all multiplications/divisions will be replaced with + or -.

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

Use math tools to train (Preplounge tool, Mimir math for iOS, Math tool on Viktor Cheng website). Train, train, and train again

Good luck!

Hi,

Basically, you need to develop 3 calculation skills:

1) Learn how to multiply double digit numbers (https://www.youtube.com/watch?v=6ndkkPZYJHo).

2) Learn how to work with zeros. Best way - always use 10^power instead of zeros

Example:

300x9000 = 3*10ˆ2 x 9*10ˆ3=3x9*10ˆ(2+3)=27*10ˆ5

Handwritten it looks not that complicated. If you get used to writing all the numbers that way, you will never loose zeros and all multiplications/divisions will be replaced with + or -.

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

Use math tools to train (Preplounge tool, Mimir math for iOS, Math tool on Viktor Cheng website). Train, train, and train again

Good luck!

(edited)

Book a coaching with Guennael

99% Recommendation Rate

284 Meetings

1,395 Q&A Upvotes

USD 319 / Coaching

caseinterviewmath.com, will rank you against other applicants by accuracy and speed. Do 10 to 15 minutes a day. You will see your rankings progress within just a few days.

caseinterviewmath.com, will rank you against other applicants by accuracy and speed. Do 10 to 15 minutes a day. You will see your rankings progress within just a few days.

Related case(s)

MBB Final Round Case - Smart Education

Solved 17.0k times
MBB Final Round Case - Smart Education Our client is SmartBridge, a nonprofit educational institution offering face-to-face tutoring services. The client operates in the US. The mission of SmartBridge is to help as many students as possible to complete studies and prevent that they drop from the school system, in particular in disadvantaged areas. The client is considering starting operations for its services in the Chicago area. They hired us to understand if that makes sense. Due to the nonprofit regulation, SmartBridge should operate on its own in the market, without any partnership. How would you help our client?
4.6 5 602
| Rating: (4.6 / 5.0)

Our client is SmartBridge, a nonprofit educational institution offering face-to-face tutoring services. The client operates in the US. The mission of SmartBridge is to help as many students as possible to complete studies and prevent that they drop from the school system, in particular in disadvant ... Open whole case

Airline Economics

Solved 16.1k times
Airline Economics We are an airline major operating out of India. We want to increase the number of passengers on all our flights. Could you please calculate the financial return of adding one more passenger per flight?
4.3 5 756
| Rating: (4.3 / 5.0)

We are an airline major operating out of India. We want to increase the number of passengers on all our flights. Could you please calculate the financial return of adding one more passenger per flight? Open whole case

REA Reinsurance

Solved 11.8k times
REA Reinsurance Your client, REA, is a reinsurance company. REA recently acquired another reinsurance company (approximatively same size): the choice of this company was notably based on its product portfolio as well as its market presence which appeared complement with REA. However, the acquisition is not well received by the market. The acquisition price is considered too high and the transaction has not been well graded. REA management asks you to evaluate the transaction.
4.1 5 957
| Rating: (4.1 / 5.0)

Your client, REA, is a reinsurance company. REA recently acquired another reinsurance company (approximatively same size): the choice of this company was notably based on its product portfolio as well as its market presence which appeared complement with REA. However, the acquisition is not well r ... Open whole case

Coronavirus Times - COVID-19 Brainteaser

Solved 3.3k times
Coronavirus Times - COVID-19 Brainteaser You and your family are faced with a challenging set of decisions. Due to coronavirus, your partner has taken a 20% paycut and you are worried you may lose your job. In addition, while daycare is still open, you are worried that sending your two children there will increase the risk of them bringing the virus back to your house, where your elderly grandparents are also staying. How would you go about thinking about this problem, and what would you recommend?
4.6 5 36
| Rating: (4.6 / 5.0)
Difficulty: Beginner | Style: Brain Teaser | Topics: Brain teaser

You and your family are faced with a challenging set of decisions. Due to coronavirus, your partner has taken a 20% paycut and you are worried you may lose your job. In addition, while daycare is still open, you are worried that sending your two children there will increase the risk of them bringing ... Open whole case

Bain 1st Round Case – BlissOttica

Solved 1.7k times
Bain 1st Round Case – BlissOttica Our client is a BlissOttica, an Eyewear Manufacturer that is looking to reach a 10% increase in profits. How would you help our client?
4.3 5 80
| Rating: (4.3 / 5.0)

Our client is a BlissOttica, an Eyewear Manufacturer that is looking to reach a 10% increase in profits. How would you help our client? Open whole case