If you want help, you're going to have to provide more info.
Update: I just saw your attached photo after I submitted my post.
It sounds like you are trying to "hide the identity of the students" and use only a roll-no to present/store marks for each subject/course.
That would indicate that somewhere in your set up you will need a table/file to relate rollNo to person/student.
To me you are working in spreadsheet mode, and Access tables are quite different.
The form and process really depends on how you intend to enter data.
If you have a form with this sort of shape for data entry
Code:
RollNo Maths Physics CA Social History Geography
You'll have to process it to put data into normalized Access tables (similar to those I mentioned in post #2.
Good luck.