How Many Moles of Chalk Does It Take To Draw a Periodic Table?

Chalk is Calcium Carbonate (CaCO₃). The molar mass is easily found from the atomic masses of the elements in the formula unit (100.7 g). Each student massed their chalk and then drew the square for their assigned element and wrote the atomic number, symbol and atomic mass in it. 

Upon return to the classroom, a new mass was found and the mass used was calculated by subtraction. Divide that mass by the molar mass and voila - Mole used. We then found the mass used by the class and then by all four of my chemistry classes. (around 2 moles).