How can I change the assignments in the syllabus in a way that is fair to the students? In my syllabus there is series of writing assignments that are worth 10% of the final grade.  Over the course of the semester there were supposed to be 4 assignments, however as a result of snow days and other extrinsic issues, the students have only turned in one of these assignments and I am not likely to be able to get any more in by the end of the semester.  

Additionally, when I designed the assignment, I did not fully appreciate how difficult it would be for the students and how difficult it was going to be to grade.  At this point it is only going to be reasonable for me to assign grades based on whether the student put some effort into the assignment (i.e., check+, check, check-, 0).

So I am left with the situation where 10% of a student's final grade could be the result of one assignment that was graded only on completion.  

As I see it, this poses 2 problems:


The final grade of the students that did the assignment will be artificially inflated, and 
the final grade of a student that missed the assignment for whatever reason will be reduced to a degree disproportional to the offence.


Is there a way to deal with this situation fairly?

(I have considered moving the assignment to another assignment group (e.g., counting it as a classwork assignment) but then I am not sure how to redistribute the orphaned points in a fair way.)
Since the assignments did not go as intended, and it is obviously not the students' fault. I would just turn this part of the grade into extra credit. For example, students who did the assignment get +2.5 points added to their final grade, and those who didn't, don't get anything.