For the purposes of this question, assume that you have a student who is aiming for a B in an introductory calculus or college algebra course but plans to take many more math classes after this. Most students in my courses match this description.
At midterm, this student will look at all his or her grades to determine which classes need more attention. If the student has a high B in the calculus or college algebra course at midterm, they are very likely to refocus their efforts on chemistry.
The end result of this is that they end up with a very low B or high C, then do very poorly in the subsequent class (C or D) due to this refocus.
How can a math educator combat this phenomenon to help their students do well and continue to do well in later courses?