How does the radio work? How is it that a different number on the radio gives me a different station?

Those numbers are actually frequencies. 94.3 (local classic rock station) is actually transmitting on the frequency 94.3 GHz (or is that MHz (GigaHertz versus Megahertz))

The radio tunes (not sure on the exact mechanics of it) into certain frequencies of your choice. Radio stations change by .2 GHz at a minimum so that signals do not mix and become faint.

Using the above example: if I tuned to 94.2, I would hear half Classic Rock and half static.

Each station is assigned a specific frequency to broadcast. The station then adds the program, ex. music or talk shows, to that frequency which it sends out through its antenna as a signal. The radio dial or number specifies which specific frequency to receive, and blocks out all the other frequencies. The radio then subtracts the station's frequency from the signal, leaving only the program.

For FM go here:

http://en.wikipedia.org/wiki/Frequency_modulation

For AM go here:

http://en.wikipedia.org/wiki/Amplitude_modulation