Steve writes:

In my previous life as a math teacher, I had a section on "Positives and
Negatives". It goes like this:
Up is positive, down is negative.
North is positive, South is negative.
East is positive, West is negative.
Big is positive, small is negative.
Clockwise is positive, counterclockwise is negative.
Right is positive, left is negative.
Red is positive (pretty color), black is negative (ugly color).
... repeat ad infinitum ...

How did you deal with the fact that the usual way of measuring rotation
in 2D Cartesian geometry is positive *counterclockwise*?

Dave