Programming Math101 : Modular Arithmetic

The below is a article I wrote for TCPHP mailing list in 2005. I thought of it today and decided to re-post it. ——————- Hi, This is the first part in a small series of requested math  articles  as it pertains to programming. Please critique the  article and give  me feed back offlist. Let me know if this is  too mathy, too ...