What we discover in research should influence how we teach in our classrooms. But for this to happen, the research must be presented in a way that is accessible and relevant to teachers. Like its predecessor, Lessons Learned from Research (NCTM 2002), this book meets this need. Its 28 chapters are adapted and updated from articles published in NCTM's Journal for Research in Mathematics Education between 2000 and 2010. The authors have rewritten and revised their work to make it clear, understandable, and-most of all-useful for mathematics teachers today.To help teachers even more, these articles have been chosen for their relevance to the eight Standards for Mathematical Practice in the Common Core State Standards. The book's three sections present chapters that relate to reasoning and proving; communicating, sense making, and using tools strategically; and modeling and problem solving. Teachers who are seeking to help students develop these mathematical practices will find insights and support in this survey of research.The chapters cover a wide range of topics, approaches, and settings, including-a case study of a third-grade teacher who sought to create a math-talk learning community in an urban classroom; an examination of middle school students' problem-solving behaviors from a reading comprehension perspective; a meta-analysis of the effects of calculator use in K-12 classrooms; an exploration of the strategies that high school geometry students employ when using a dynamic software program; an analysis of a professional development initiative designed to help teachers select and implement cognitively challenging tasks. Mathematics teachers at all levels will find examples of research that is relevant to the challenges they face. This book, along with its forthcoming second volume, enables researchers and teachers to meet on common ground to improve mathematics education for all students.