We used large industrial fans (75 horsepower & 72" diameter) on some of our equipment where I used to work.
I used programmable logic controllers and drive converters on them to either forward or reverse the air flow in a homogenizing oven for aluminum logs (oven large enough to park a bus in).
I know, manipulating electricity to change a fans rotation sounds like 'cheating', but they still ran either way.
Reverse the polarity (on things wired to handle it) and the device will run "backwards" Years ago I was running a CNC turret punch press in a sheet metal shop, the owner came to me with a piece of metal (thicker and harder than normal ) and told me to try and punch a 5/8 hole in it, punch went about 1/3 through and stopped, only way to get it out was have the maintenance guy swap the "red" and "black" wires, then when I pushed the start button the punch lifted, instead of trying to go down.
As for the "number thing" I understand that it's eliminating possibilities as you make choices, but how the HELL does it get the right number behind the random door I pick ? I opened the other doors and they had different numbers, ARGGHH, I'm going to try again !