Subject teachers enter their own marks against the grading scheme set for that class. Nobody collects paper slips from the staff room and nobody totals a column by hand at eleven at night.
The exam before the marks
An exam carries its type, its dates, and maximum and passing marks. Each class-and-subject sitting is scheduled with its own date, time, room and maximum, so a practical marked out of thirty sits correctly beside a theory paper marked out of seventy.
A teacher enters a sheet, not a form
Marks go in for a whole sitting at once, down the class list. Absent is a state of its own rather than a zero, which matters when the difference decides whether a student is failed or re-examined.
Only their own
A subject teacher sees the subjects they teach. The staff room does not need a convention about who is allowed to open which file, because the software already knows.