When I taught 7th Grade Medieval world history, I taught feudalism using gummy bears. Feudalism is just one economic system in history so I wanted to compare and contrast it to other economic systems, so students could fully grasp the complexity and nuance of feudalism (and how restrictive it was and how it impacted societal structures).
I had students read a few chapters from Dr. Eric Nilsson;s book on economic systems. I found this free reading by googling: Nilsson, Eric “ Different Economic Systems” (it will pop up as a pdf from CSULB's economic dept). Its a challenging reading, but completely manageable if read together in class or broken apart. Or you can have students research different economic systems andtake notes.
Use the presentation to introduce and explain gummy bear project (Note: I also did this for political systems).