A very odd calculator app.
The idea for this app came to me when I was brewing beer using a digital thermometer. I hadn't bothered to hook the thermometer into a microcrontroller, so I was just reading the voltage directly, and calculating the degrees in Fahrenheit.
The formula was pretty simple: (V * 51.2 - 20.5128) * 9 / 5 + 32
Here's what that looks like on Mainframe:
Hopefully you can see that all the parts of this formula are editable - each number, and "Voltage" is represented by x and assigned off to the side via x=
Cool, huh!?
There's special handling for π - rather than convert to a number, it is held symbolically for "as long as possible", so calculations involving cos/sin can be exact.