LESSON PLANS. These papers are intended to support leaders of a session or progression of sessions aligned with the Math Circle core values. Authors must identify the target audience of the session, briefly explain the underlying key mathematical ideas and provide references for further understanding of base material, outline the intended implementation of the activity, and reflect on successes and challenges of the actual implementation of the lesson. The inclusion of participant work or session video is strongly encouraged. Supplemental materials such as handouts, presentation notes, and materials lists, should be included as appendices.