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
I’m aware of how computers use numerical methods to get numbers that are good enough for a given precision.
I meant more like a robust way to create physical slide rules for arbitrary uses. Here’s a set of tables of baking ratios, I want to comfortably look up x for a known y. That kind of thing.
I think what you really want is nomogram, which is like a non-moving sliderule in the form of a graph, which is great for "If I have X of thing A, and Y of thing B, how much of thing C do I get/need?" questions like baking ratios.
Unforuntately, I can't really find an nomogram generators online that I can get to work (though that might be a me-problem, and not a website problem)