Regardless of the direction that you take, your introduction should engage children, arouse curiosity, and set a direction for the lesson. The children should, by the end of your introduction have an idea about the focus of the lesson and what they will be doing. The introductory activity should also help you reaffirm your thinking about your student's background knowledge and readiness for the experience. This is the bulk of the lesson where children are immersed in exploration of topics or concepts. This is the primary activity of the lesson.
Students work with one another to explore ideas through hands-on activities.
The teacher is the facilitator and observes and listens to students as they interact. The teacher asks probing questions of the students so that they clarify their own understanding of major concepts. Additional questions may be asked to redirect students' investigations when necessary. Adequate time for thorough investigation is critical at this time. This is the meat of the lesson.