To better improve the experiment, the duration of heating should be time because it may give an accurate weight rather than continuously burning it. He should show his final answers in significant figures since the results he gained are of different number of sig.figs.
After doing the experiment, I have learned that when magnesium is burned and combines with oxygen, it would become magnesium oxide and the weight of the product would be heavier. I learned that the empirical formula gives the simplest ratio between 2 or more substances / elements. For example, the magnesium oxide has an empirical formula of MgO. Although the empirical formula of MgO may not be the same, the results from the experiment are somewhat the same. The experiment gives a estimate of how the empirical formula or the ratio of the 2 substances are.