NavList:

Bill you wrote:

"I'm confused.  20d 30' 15" would be 20.50416667. -20d 30' 15" would be
-20.50416667.  Where does -20'30'15' (all minutes) come from?"

 

It's just a generic separator symbol in the display (actually it's a small box --looks more like a degree symbol than a minutes symbol but I have no way to represent that in plain text so I just used a single quote). The point being that when you ENTER 20d30'15" you SEE 20-mark-30-mark-15. This is a nice visual check on data entry. This is only on the newer models. I like it better than the TI system which requires you to know the dd.mmss format and permits less variation and has no obvious way to catch entry errors. For example, if a student mistakenly enters 23d2'45" as 23.245, the error is by no means obvious. Also, if I get up from my calculator and come back to it a few minutes later and see 20.3015, on a casio calculator that can only be the decimal representation of the angle. On a TI, maybe it is, maybe it isn't... On the older models, as Alex mentioned you have the option, at no extra cost, of entering angles with tenths of minutes. This doesn't seem to work on the more recent ones. Pity! These are minor issues, but they're clearly issues that people designing these devices have put some serious time into. And I find that rather amazing for something as old and moldy --and yes, minor-- as degree-minute-second conversions.

 

And you wrote:

"Perhaps it's just a difference between Chicago and Associate Press style
manuals.  A co-worker of Kurt Vonnegut, Jr. at GE taught me that spaces
between letters and commas--like advertising account executives--add no
information to the process but do on occasion make things clearer.  Of
course he worded it better. "

 

LOL. Yes, it's nothing more than that. I like the casio entry system a bit better, but only "a bit".