Hi,
Here I've uploaded some written case samples here:
https://www.dropbox.com/sh/zor4m49eyx5qxal/AABeUN6mtiGkWhEklRjszX2Oa?dl=0
Ask me for a password
The best way to prepare is the following:
- Prepare for a regular case interview - it helps a lot. Basically, prep lounge website is about it
- Practice reading cases fast and prioritizing the information. I found useful two sources:
- Written cases you'll be able to find in google or in case books. I've seen a couple in "Vault Guide to the Case Interview" and "Insead Business Admission Test"
- Harvard cases - either buy or try to find online. You can find a couple of MIT cases here for free: https://mitsloan.mit.edu/LearningEdge/Pages/Case-Studies.aspx Unfortunately free cases don't have the prep questions.
Check if the calculator is allowed. So far it was. If not - you have to train mental math. Basically, you need to develop 3 calculation skills:
1) Learn how to multiply double digit numbers (google fast math tips or The Veda math).
https://www.youtube.com/watch?v=PYrgjMubh-c
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
4) Use math tools (Mimir math for iOS, Math tool on Viktor Cheng website) to practice. Train, train, and train again
Good luck!
Structure Anything 
