This book addresses Problem-based Learning (PBL) in elementary schools and reveals how this can promote elementary students' development in critical thinking, creativity, communication, collaboration, and citizenship, also known as the 5 Cs. Through teachers' interviews, the book explores which PBL strategies promote skills and knowledge gains when students collaboratively investigate authentic open-ended problems. It also uncovers peer-to-peer relational learning and other strategies used in PBL classrooms, and it examines their importance to public education. The book paints a lively picture of student-centered learning, drawing upon frameworks, best practices, experiences, processes, strategies, and research results. Firsthand accounts of best practices in PBL instruction connect this pedagogy to theory, research, practice, and policy. It explores teacher instruction in the early years of schooling that purposefully fosters student-centered learning, real-world relevance, and collaboration in accordance with capacities expected of successful 21st century graduates. This book supports the implementation of PBL in elementary schools and promotes increased student engagement and achievement, as well as college and career readiness. This book is of interest to practitioners seeking information about PBL pedagogies for elementary grades, such as teachers, teacher mentors and trainers, (school) leaders, and policymakers, as well as anyone interested in pedagogic strategies that advance critical thinking, creativity, communication, collaboration, and citizenship capacities.