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
There's a bit of a difference though between those computer driven iterative digital numerical methods and an analog continuous geometric object. It's like comparing pixel density and film grain. At a fine enough precision they become difficult to distinguish, but they are not the same. You could definitely use iterative methods to build a "continuous" solver at an arbitrary precision. We pretty much have to do it that way for any signficantly complex function.
Sorry, this comment got away from me and feels kind of incoherent now. I'm just trying to say that analog and iterative digital methods have subtle differences that one should remain aware of.