Bridging the gap between the mathematics learned in college and the mathematics taught in secondary schools, this unique text and resource is designed to help preservice and in-service teachers gain the knowledge they need to engage their students in learning mathematics in a multifaceted way that is interesting, developmental, connected, deep, understandable, and often, surprising and entertaining . Six content strands are covered: Number and Quantity, Algebra, Functions, Modeling, Geometry, and Statistics and Probability. Written in an informal, clear, and interactive learner-centered style, the text includes helpful pedagogical features. Launch Questions at the beginning of each section capture interest and involve readers in learning the mathematical concepts. Practice Problems associated with what has been learned in the chapter provide opportunities to complete proofs that are mentioned but not proved and to apply what has been learned to solving real-life problems. Questions from the Classroom bring the content to life, such as the deep "why" conceptual questions that middle or secondary school students are curious about, questions requiring analysis and correction of typical student errors and misconceptions, questions focused on counter-intuitive results, and questions that contain activities and/or tasks suitable for use with secondary school students. Changes in the Second Edition. . The content is substantially restructured content and updated throughout. New problems and more illustrative examples are included. Answers for some of the problems are provided. The Common Core State Standards for Mathematics content areas are covered though the text is not closely aligned to the Standards per se given their currently in-flux status.