2. Another one is to use Mendeley. In addition to being multi-platform, it also has a web site where you can sync your PDFs for online access. It also extracts the metadata from your PDFs (like title, authors, journal titles) and fills in many fields for you. You also have PDF renaming options.

3. Finally, a lot of people use papers: http://mekentosj.com/papers/

I haven't tried any of these though, so I wouldn't know which one to recommend. I personally just organize the PDF's by fields of research and name each one as the title of the paper. It helps having hard copies as well :D

This trick does require some memorization though, and also requires the number given to be a perfect cube. You need to memorize the cubes of the numbers 0 through 9 (or be able to figure them out on the spot). This information is contained below:



Note that the last digits of the cubes on the right have all the numbers 1 to 9, but no number is repeated. Here is how to find the two-digit cube root of a perfect cube.

Take a number, such as 658,503 which is grouped into two parts.

1. Looking at the number we see it ends in a 3, and according to the table only 7^3 ends in a 3, thus the last digit of our number is 7.

2. Next, ignore the last 3 digits of the cube, so consider 658. Compare these digits with the table above. Note that 658 fits between 512 and 729. You always choose the smaller one, in this case 512 which happens to correspond to 8^3.

Thus, the last digit is 7 and the first digit is 8, giving an answer of 87.

Normally this trick is used for six digit perfect cubes. To help understand how this works, ask yourself - What is the last digit of (10x+y)^3? Clearly it is y^3 mod 10 (how does this relate to #1?).

Another Example:
In 474,552 we have that 343 is the immediate smallest number from 474 so the first digit is 7.
The last digit in 474,552 is 2 and only 8^3 ends in a 2, so the last digit is 8. Hence, 78^3=474,552.

Part 1



Part 2