We are coming to the end of our human body unit. It's been such a fun curriculum for us, and a steal at only $12 (!)--full of experiments, crafts, and great books. I last posted about the circulatory system unit. Since then, we've done the respiratory system, digestive system, and urinary system. Here are some highlights. Respiratory system: We recorded an experiment about breathing and heart rate at rest vs. after some jumping around. We tried to use homemade puffy paint to make a model of the respiratory system. The puffy paint (shaving cream and liquid glue) didn't stay puffy, but anything with paint is still fun! We tried twice to make a model of the lungs and diaphragm using a water bottle and some balloons. Neither worked! So we watched a video of someone making it on YouTube. Oh well! Digestive system: I guess I only have one picture from this unit, but it was a fun one! One activity was mashing up graham crackers in a bowl, with a little...