suggestion: allow simple math in some number fields

[DeadlyKitten37]

The main one I want this for is the product output field

I am thinking nothing more the basic +-*/

example use case the current product amount uses 2.687 machines, if I do (current output) /2.687 then (new output) * 3 I will have exactly 3 machines required

example 2 the current product amount required 20 items per sec in, if i do (current output) / 1.333 then I will input exactly 1 belt.

[KiwiHawk]

You can already do this

If I want it to use 3 machines, rather than 8: