Snap Circuits, by Elenco, are a great way to introduce students to circuit building. While the kits include project ideas, this activity links student building back to the vocabulary and circuit parts studied in the middle school classroom. This exploration allows students to explore closed circuits, changing voltage and resistance in a circuit, and series and parallel circuits. This can serve as a reinforcement exercise, or an introduction before building with "real" circuit components.
This exploration is designed to work with both Snap Circuits and Snap Circuits Jr. My students use the AC adapters, but you can easily substitute batteries.
Your download is a Word document, so it is easy to modify if you want to change the directions or remove a topic. I include series and parallel circuits last, so it is easy to remove this last page if you are working with younger students. I also include an answer key for the student questions.