Protected Cells
If the worksheet is protected, then the cells with formulas are protected. If the worksheet is unprotected, then there is a chance that formulas will be deleted, breaking the grader.
Worksheets 1-12 - Where Not to Type
The image below shows the areas that are safe to type. Do not type in the darkly shaded areas of the image. NOTE: these areas are not darkly shaded in the actual workbook.
12-16 Help Pages
