Ok, hopefully I can get this all done in one blog! I really enjoyed the predator-prey models and I am excited that both are activities that I can use with my kids at school. The java simulation was interesting to see how the patterns could be graphed two different ways, and how you could use one to help explain the other. It was also cool to play with the numbers and see what would happen to the populations respectfully. The activity we did with the beans will be so great to do with my students. We do one somewhat like this, but not as involved. As you said, there are some modifications that can be done to change the activity and make it more specialized. Similarity between them, graphing is done (but different graphs, which will help us with reading different graphs) and relationships between generations is shown. I liked the beans better for the practical use of it in my classroom. Most of my students would enjoy and benefit more from actually doing the activity rather than seeing the changes in graphing on the computer. The activity we performed this afternoon was very interesting, I have not used a spectrometer before. We do talk about light wavelength, so the color - complementary color chart I can use. I am limited as to the chemicals I can bring to my building and allow the students to use but maybe I can modify the numbers so they can use those and do some of the math.