Old Dad makes a great point.
There's also the reality that some community college classes aren't as demanding as equivalent classes at colleges and universities. Thinking about it now, my son took a couple classes at the CC last year, and they definitely didn't cover the amount of material that perhaps they might have. When asked about the slow pacing, one professor told my son that he had to move through the material very slowly in order not to lose his students.
So that's one end of the spectrum, and the problem stems directly from students who lack skills in mathematics.
The other end of the spectrum is when too much material is covered too quickly. IMO, racing from one topic to the next doesn't allow students time to ponder what they've learned. IMO, this process makes it hard to acquire an understanding of how what the topic at hand is connected to different topics in the subject itself, as well as to other subjects. (Okay, this paragraph is a bit OT)....
