A tool used to help students in practicing calculations of empirical formulas. Students first cut along the vertical lines up to the bold horizontal line. This results in four "flaps". I have the students label the outside of the flaps (once folded down) with the words "Mass, Mole, Divide, Round", to better remember the order of the steps. I then get them to open the flaps back up and I go through the skeleton notes given for each step (red words can be removed). Then, I model by working out the examples given at the bottom of the foldable, one at a time, with each example type followed by practice problems of the same type.