Hi,
I'd like to encourage students (especially upper sec, JC,
poly, undergrad levels) to read this (over a period of
time as it is a really long article):
http://www.math.vanderbilt.edu/~schectex/commerrs/
Do make a mental note of your errors so that you'll
reduce the likelihood of committing them in exams.
To make this discussion more meaningful in our context,
I'd like to invite all to highlight some of your own errors.
Thanks in advance!
Cheers,
Wen Shih