Numbers for simple school data

Hey,

I'm completly new to speadsheets and have beem asked to compare my subject (I'm a teacher) to another's results.

I just want to be able to get the:

- percentages of A-Bs and A-Cs etc per the two classes

- if possible, highlight where my subject was higher/lower than the other results for that student (I've removed the names column for purpose of showing my data)

I am using numbers 3.1 on my Mac. I'm sure there is most likley a very simple way to do this, but I am very unfamilar in the world of spreadsheets!

Can any offer any much-appreciated help?