I have a formulas question which a part has several answer boxes. To calculate the mark I use the following code in "Grading variables" section:
dabs = map("abs",_d);
rawmark = map("<",dabs,.01);
mark = sum(rawmark)/len(rawmark);
This is fine as long as student enters a number in all boxes. Let's say I have three boxes and a student answers two of them correctly, but leaves one box empty (or enters something other than a valid input e.g. a letter or uses / for decimal instead of .). Then the above code fails to account for the correct answers and gives zero mark.
Is there an easy way to fix this issue? thanks