In future it may be wise to put all your CV/resume/job questions in one thread instead of creating a thread for every 'should I put xxxx on my resume'. Just a thought for consideration.
Anyway, for my first position I put down study scores for subjects that were relevant to the job I was going for. In my case, I applied for a teaching position as a Digitech teacher so it made sense to note my 40 in Computing. If you do a uni course then apply for a job, it makes no sense to put down grades for every subject you do. A simple average which reflects a commitment to studies over a period of time is better.
The question you should be asking yourself before you put something (anything, really) down on a CV: Is it relevant to the job i'm applying for, or am I just putting it on there for the sake of it? If it's the latter, it's probably not a good idea to put it on. Again, a CV is a summary of facts about you and your achievements that demonstrate you as suitably qualified/able to do the job. Resumes/CV's are used primarily as a shortlisting tool (in addition to a cover letter) to progress applicants to an interview.