This field-spanning book will set out the broad advances in knowledge which have accumulated in the 21st century through the sustained exchange of ideas and collaboration between mathematics education researchers, considering both european and global perspectives. It is split in to three main sections focusing on content domains and processes, aspects of mathematics teaching and learning, and linguistic and social perspectives, and concludes with two lively international discussion chapters. Each section will include coverage of recent developments, current status and future outlook of global research making this book a fascintaing compendium of state of the art mathematical knowledge.