I gotta post something, so I'll post the mechanical calculator that the flight school wanted me to get. How it works is that you can set ratios in the dial and multiply them. In this picture, it's 60:10 (or 60:1.0) so I can take any number from the inner circle in minutes and find out how many hours that is equal to on the outer circle.
There are also other things on this calculator, including a wind vector calculator, and charts. Most pilots don't use these anymore, but they still wanted me to know how to use one
In my experience, this is one of the devices that only creates more confusion in what already is a high stress environement. I get what you are saying, but i doubt there is a single pilot under the age of 60 that would ever use this device willingly. The heirarchy anymore is the in suite avionics, then secondary instruments, then Ipad, then, asking for vectors.
Its like an abacus. Theres just very little use for it anymore. And maintaining proficiency is only for the test.