Problem-based instruction (PBI) is a research-based, student-centered instructional strategy that uses rich mathematical tasks to connect students' previously acquired math knowledge to new mathematical concepts. Unlike traditional teaching and learning strategies, PBI facilitates learning by making connections between mathematical concepts and real-world applications rather than through noncontextual, rote learning of skills, steps, and equations. This practical resource is an informative instructional tool for secondary mathematics teachers and teacher educators seeking to deepen their students' understanding of, and engagement with, mathematical learning. Highlighting both teacher and student perspectives, the text provides an overview of the PBI instructional strategy that includes best practices, guidance for implementation, and a companion website with more than 50 downloadable resources. In addition, readers will find 12 teacher-created sample lessons with prepared resources and detailed instructional guides. While written for novice PBI users, this book will enhance the instruction of teachers at all levels. Book Features: (1) Provides 12 ready-to-use sample lesson plans aligned to the most common secondary mathematics topics written by experienced classroom teachers; (2) Focuses on the practical implementation of problem-based instruction specifically for middle and high school mathematics instruction; (3) Includes a template to guide readers step-by-step through creating their own problem-based lessons; and (4) Access to a companion website with more than 50 editable, online resources for easy classroom implementation.