Big project, you'll have to work as a group on this one! Over at Smart Chick Teacher's Blog, kids estimated how many sheets are on one roll of toilet paper. Next, they laid out their sheets to form one large four sided shape (square or rectangle, depends on how many sheets are on your roll). Then, they measured and found the area and perimeter of their four sided shape! Check it out here!
You can also find the volume of the roll, use the formula for a cylinder! Check out Mark Tully's project here!
Note: You could also do this activity with a roll of paper towels.