Sorry, mis-spoke myself - I meant later in the week.  I want to let this sit and then expand it.<p>I intend to turn this into a growing series, related to this idea: <a href="http://news.ycombinator.com/item?id=672067" rel="nofollow">http://news.ycombinator.com/item?id=672067</a><p>There I thought I'd start with fractions, basically from the ground up, but I think that's wrong.  I think I want to engage people first, then "drill down" on demand.  The comment about wanting more about the cardinality, the C.H. and related stuff is what I was looking for.<p>Perhaps I can do one a week.  Or so.