No, my math is not in error, you are apparently just too ill-informed (the least personally offensive term I could think of to use) to be able to follow it.
I was using a simple low wage example to illustrate the point that Social Security is a bad deal. The higher the wages a person earns the worse the deal becomes.
As you go back and try to figure out where your calculations failed... try factoring in compound interest. Yeah, retiring as a millionaire is fairly easy, with patience and foresight. Compound interest is a beautiful thing, when you are collecting it instead of paying it.