In a sentence, the comma denotes a continuation of that sentence, whereas the period means full stop. Why should it be different for numbers?

A comma means you are continuing on the whole part of the number, whereas the period means the whole part is over, now on to the fractional aspect.

32. Loved MAD when I was younger. Been hoping to dig up my old stash one of these days, if only I knew where to find it in my parent's basement.