If there was one stubborn "kink" in my thinking, which I had to iron out; it was this one! "What comes after '19'?" "20?" Well, yes... IN DECIMAL! If you're in duoTRIGESIMAL, though, it is NOT "20"! It is "1a"! "Ah-tuhn". For the pronunciation of this number, think "autumn", but put the "n" sound for the "m" sound. Base thirty two "1a" equals decimal "42" (which is 32+10).
Left thumb down, and (I use my thumb muscle to help hold these fingers down) my right ring and index fingers down. (In fact, I use a "curling" motion to "curl" my fingers up against my thumb muscle and hold them down. Also? Again: I pull my middle finger down OVER TOP of my thumb muscle. Why? Because if I stick it up, it looks like I'm giving someone the "middle finger"! And I want to do everything I can to avoid that misunderstanding! Therefore, when it is OVER TOP of my thumb muscle. That way, I still know not to "count" it - even though it is not sticking up. Please see the post on Decimal: "10" - or "ten", for a picture of what I am talking about.