Apologia Chemistry: Moles and Percent Composition Calculations

Today we went over the calculations for the mole lab and percent composition lab we did Tuesday.
The kids converted grams of iron nails, table salt, baking soda, mossy zinc, aluminum foil, and copper shot into moles.  The calculation is to divide the mass of the item by its molar mass.  For example, calcium has a molar mass of 40 g/mol.  If the student measured 5g, she divides 5g/40g/mol, or 0.125 mol. (moles)  Here is the data chart.
Mole Lab
Item       Formula         Mass        Molar Mass        Moles

The percent composition lab requires the kids to determine the molar mass of each hydrate and  the percent of water in the hydrate.  Next the student determines the amount of water removed from heating.  Finally, the teens calculate the percent error.  Here is the data chart.
Percent Composition Lab
Chemical      Formula     Molar Mass      Mass Before     Mass After     Percent Water   Percent error

Below is my attempt to take photos of all of the steps to teach this process.  The teens must write the formulas correctly, calculate the molar mass, determine the percent of water and finally compare the experimental results with the theoretical results.  Yes, this took all of the class period.