I'm a math teacher and want to create a spreadsheet that functions as a test
I can grade automatically. My classes of 25 students per class can all bring
laptops into the classroom. I want them to open a spreadsheet I'll create,
where they WILL NOT have any access to any Excel functions. On the
spreadsheet there will be several hundred math problems involving fractions,
percents, decimals, etc. I want them to do the actual math work on scratch
paper, and just key in their answers in select spaces alongside each math
problem on the spreadsheet.

So my goal is to have some kind of password protection where ALL Excel
functions are shut off, so that they cannot use Excel to do the math work.
Then, I will unprotect the documents and grade them automatically, writing
back onto each student's version of the spreadsheet a check symbol or an X
mark next to each problem, until they re-do all wrong ones.

I tried Calculation Options (Office 2007) but couldn't get anywhere with it.

Thanks in advance.