When I studied "new math" in the old days we called them "tens and ones." Maybe I've just forgotten, but I don't think we used the term "place value." Then again, the "new math" I studied in grammar school was discontinued by the time I reached junior high.
The word digit, though — it's been around a while. And I thought of it yesterday not only because the temperature was in the single digits but also because the temperature most affected my digits. My fingers and toes were aching with the cold after my single-digit walk (nine minutes, tops) from Metro to the office.
So this post is a paean to digits, to the fingers and toes, the most exposed; to the basic unit of measure, the original abacus; to the root of digital and all the good things (!) that derive from it.
We start with the body and move ever outward. Just think how far we've come.