Between my website, Facebook, and other social media, I tend to get into a LOT of conversations about science, especially controversial topics such as climate change, genetic engineering, evolution, vaccines, nuclear power, electromagnetic fields, etc.
Understanding chemical and physical changes is a strange part of science. Once you learn to use chemical equations, it is so simple that no one even thinks about it. Before you learn to use chemical equations, it is so complex that most people don't really understand it. For a better view of that, you might also read Changing How We Look at Changing.
This is a cool science trick that will let you know the number of sections in an orange (or other citrus fruit) before you slice it. It makes a fun trick that seems like magic, but is actually just a matter of careful observation.