[dbz]

Oh yes I agree. I personally am a math guy. My algebra two teacher was...well...Let's say that I sat in the back of the class the entire year and just corrected him several times a day. Almost all of the people who left that class struggled to understand concepts of their next math course because they:

1) Didn't have a solid understanding of algebra. and 2) Didn't even learn all of the algebraic concepts.

I was fine (because I could recognize the concepts even though he made a TON of mistakes) and skipped (precalc/) trig (which I learned during..) and went right on to AP calc . But the point is that the fact that the teacher made so many mistakes led to the students not being able to comprehend slightly higher level math. (and him being fired)