Introduction Part Theoretical and Methodological Perspectives on Teachers' Learning through Teaching Chapter 1 Roza Leikin and Rina Zazkis Teachers' opportunities to learn mathematics through teaching Chapter 2 John Mason Attention and Learning about teaching through teaching Chapter 3 Ron Tzur What and How might mathematics teachers learn via Contributions to closing an unspoken gap Chapter 4 Roza Leikin Learning through teaching though the lens of multiple solution tasks Part Examples of Learning through Pedagogical mathematics Interlude 1 Chapter 5 Rina Zazkis What have I Mathematical insights and pedagogical implication Chapter 6 Marcelo Borba and Rúbia B. A. Zulatto Dialogical education and learning mathematics online from teachers. Chapter 7 Carolyn Kieran and José Guzmán Role of task and technology in provoking teacher A case of proofs and proving in high school Algebra Chapter 8 Nick Jackiw and Nathalie Sinclair Learning through teaching when teaching Discursive interaction design in Sketchpad Chapter 13 Robin Marcus and Daniel Chazan What experienced teachers have learned from helping students think about solving equations in the one-variable-first algebra curriculum Part Examples of Learning through Mathematical pedagogy Interlude 2 Chapter 9 Michal Yerushalmy and Shulamit Elikan Exploring reform ideas of teaching Analysis of videotaped episodes and conversations about them Chapter 10 Peter Liljedahl On rapid professional cases of learning through teaching Chapter 11 Lara Alcock Interactions between teaching and pedagogical content knowledge for Real Analysis Chapter 12 Helen Doerr and Stephen Lerman Teachers learning from their The case of communicative practices Chapter 14 Dave Hewitt Expanding a repertoire and making choices Conclusion.