The first problem you posted, I agree that the context is daft – because it’s too brief to present any sort of challenge to reading and comprehension, rather than because it doesn’t make sense in itself. All sorts of things in the real world make no sense but still happen, after all! I don’t have a problem with “1 radian” – the assertion that mathy people measure angles in multiples of pi holds true only when they’re *nice* multiples of pi.

Next question: whatever “symmetric with respect to the origin” is supposed to mean, it probably shouldn’t. I couldn’t begin to guess. Do the mean symmetric in the x axis? y? both? rotational symmetry, and if so of what order?

Third question: if “D_2″ means “enlargement* with scale factor 2 about the origin”, then the wording is redundant. If it means “enlargement with scale factor 2″ then it’s a bad piece of notation as it doesn’t describe a transformation without further information. Either way I really don’t like this sort of unglossed semi-standard notation stuff.

* we brits say “enlargement” rather than “dilation”

I grew up learning math in math class, and using math in science classes. I don’t know how I can be comfortable, how we can be comfortable, doing the modeling where the skill acquisition is supposed to be taking place.

The radian problem would have been far better without the context, and with a multiple of pi radians, or with degrees.

I think the dilation is the most egregious. What does D_2 mean, is this some sort of New York terminology. Is the math equivalent of “ring ding”.