I recently spent the day at Armstrong Elementary School in Westborough, MA. My visit came in the midst of the first graders unit on rocks and soil, so we had a blast.
First the students put on their thinking caps to decide whether or not some mysterious-looking objects I gave them were rocks or not. They did a great job of practicing their reasoning skills, so it was really hard to fool them.
Then we looked at three soil samples labeled A, B, and C. The students compared them and noticed how they were similar and different. Then I told them where the soil samples came from—a sand quarry, my backyard, and their school playground—and asked them to guess which was which.
Those students paid close attention to even the smallest details , and they picked up on all the important clues. Every single class got the answer right. Hooray!