Hi Q:
It sounds to me like you might be a teacher(I retired after 38 years!) I'm assuming 80 values or grades. If it's an AVERAGE you are looking for just go to where you want the average and type the formula =AVG(A1..A80) and that will give you an average. It will SKIP any 'blanks' so if you intend to 'punish' students for not doing something then you MUST add a zero in the grade blank.
Use Barry's directions to change to a % but I never bothered - I just let the thing run as a decimal and then 'changed' to a % on the Report Card.
If you want a copy of one of my grade books just send an email to
[email protected] and I'll send you one back.
Hope this helps. Please let us know.
Blessings, Dean