On: Yan tan tethera pethera pimp – an old system for c...

[schoen]

It's kind of amazing how thorough this particular area of reconstruction is: https://en.wikipedia.org/wiki/Proto-Indo-European_numerals

(and the continued astonishment I get at Indo-European languages being native from Iceland all the way to India and Siberia -- maybe I should say "from Iceland to Ireland, Italy to Iran and India")