Logan:
The modulus is easy to use. Basically, what I'm saying is that if $i/4 does not have a remainder (i.e. 4, 8, 12, 16...) then it does whatever if it's true, and whatever else if it's false.
I have no ideas for articles, do what suits you. But before you try and write one, I'd take a look in the Echo Lounge at the post about articles and go from there.
~Brett