-Offers a theory of secondary mathematics teacher learning in schools to achieve ambitious and equitable mathematics in their classroom, drawing on sociocultural learning theory. -Explores teacher learning as well as the role of context in teacher learning, using closely-documented case studies from across the US. -Offers researchers and scholars new theoretical and methodological tools for the elusive phenomenon of teacher learning, and instructional leaders and coaches practical examples of how teachers shift their thinking and practice.

-Offers a theory of secondary mathematics teacher learning in schools to achieve ambitious and equitable mathematics in their classroom, drawing on sociocultural learning theory. -Explores teacher learning as well as the role of context in teacher learning, using closely-documented case studies from across the US. -Offers researchers and scholars new theoretical and methodological tools for the elusive phenomenon of teacher learning, and instructional leaders and coaches practical examples of how teachers shift their thinking and practice.