Apologia Chemistry: Coins and Percent Composition

Percent Composition with Coins lab helps kids understand three different aspects of an empirical formula.  The demo uses three quarters, three dimes, and three nickels.  Each coin is 1/3 of the total coins.  The kids can determine the percent each coin represents of the total money.  Lastly, the kids can determine the percent by mass of the coins of the total coins by weighing them.  After Christmas, I'm going to do this demo/activity with the kids to remind them about moles, percent composition, and mole ratios of elements in compounds.  I made up cups with the coins.  I think this activity will drive home empirical formulas.  We'll see. (The baby bottle has loose change.)