I'm teaching a Global Ag. Unit to my Principles of Ag. Science class and I really want to find a commodity trading activity to drive the concept home. I used something a few years ago that gave the kids what they had to sell and what they needed to buy and they had to make it all work by trading with different "countries". I can't find this anywhere (I've moved to another district since then). If anyone knows what I'm talking about please let me know, or if you have other ideas, I'd love those too!!