This contributed volume presents a collection of essays honoring Matthias Ludwig and his contributions to the field of mathematics education. He is particularly renowned for his pioneering work on making connections between mathematics and reality tangible and accessible, both inside and outside the classroom. His areas of expertise encompass the areas of “Modelling & Applications”, “Diagnosis & Support”, “Education & Technology”, and “Math Trails & Outdoor Education”. The chapters in this book, written by experts in these fields, are organized into four corresponding parts.

This insightful book comprises many ideas, concepts, and approaches, showcasing Matthias Ludwig’s vision for active, learner-centered, and hands-on mathematics education. Therefore, it is of interest to scholars, researchers, and all readers with an interest in contemporary mathematics education.

Simon Barlovits is a researcher in mathematics education, working at Goethe University Frankfurt. He worked on his doctorate on the technological support of mathematics trails through mobile learning. Beyond the fields of outdoor mathematics education and the use of digital tools in mathematics education, his research interests also include mathematical modelling, particularly in the context of sustainability.

Simone Jablonski is an assistant professor of mathematics education at University of Paderborn. Prior to this position, she worked as a researcher at Goethe University Frankfurt, where she completed her doctorate on mathematical giftedness. Her research interests include mathematical modelling and reasoning, particularly in the contexts of outdoor mathematics and Fermi problems, as well as the use of digital tools in mathematics education.

Joerg Zender is a postdoctoral researcher at the University of Cologne, where he works on mathematics education. He completed his doctorate on mathematics trails and has taught and researched in several German cities, including Frankfurt, Koblenz, and Wiesbaden. In addition to his university work, he continues to teach mathematics at school level. His interests include outdoor mathematics, problem solving, assessment, and the popularization of mathematics.