Comment by bariumbitmap

Interesting idea, particularly the prompting for uknown quantities, but GNU units already does a pretty good job of this.

https://en.wikipedia.org/wiki/GNU_Units

Calculations aren't quite as short as "1mA 3K", but pretty close to it.

    You have: 1mA 3kohm
    You want: V
            * 3
            / 0.33333333

It has long and short SI prefixes, scientific notation, implicit multiplication, and a history dating back to Unix itself.

By the way, one of the example calculations (calculation of 205 Hz) is too high by a factor 10.

    You have: 1 / (2 pi 0.5microF sqrt(11kohm 22kohm))
    You want: Hz
            * 20.461734
            / 0.048871712