1. Through cooperative exploration, we found the law that two kinds of objects are arranged at intervals.

2. Can use this law to explain the phenomena in life and solve the problems in life.

3. Students experience the process of exploring laws and master the methods of observation, analysis and comparison in hands-on operation, independent exploration and exchanges and cooperation.

4. In the process of solving problems, feel the diversified ideas of problem-solving strategies. Cultivate students' enthusiasm and curiosity for discovering and applying laws, as well as their interest in learning mathematics.