Notes on Contributions -- Section I: Review and Critique of Mathematics Education in Multilingual Contexts -- Teaching and Learning Mathematics in Multilingual Classrooms: An Overview -- Mathematics Education and Language Diversity: Past, Present and Future -- Mathematics Education, Language and Superdiversity -- Section II: Policy and Mathematics Education in Multilingual Contexts -- The Intertwining of Politics and Mathematics Teaching in Papua New Guinea -- Language of Instruction and Learners’ Participation in Mathematics: Dynamics of Distributive Justice in the Classroom -- Transition of the Medium of Instruction from English to Kiswahili in Tanzanian Primary Schools: Challenges from the Mathematics Classroom -- Section III: Learning Mathematics in Multilingual Classrooms -- “x-Arbitrary Means Any Number, but You Do Not Know Which One”: The Epistemic Role of Languages While Constructing Meaning for the Variable as Generalizers -- Multilingual Students’ Agency in Mathematics Classrooms -- Students’ Use of Their Languages and Registers: An Example of the Socio-Cultural Role of Language in Multilingual Classrooms -- Productivity and Flexibility of (First) Language Use: Qualitative and Quantitative Results of an Interview Series on Chances and Needs of Speaking Turkish for Learning Mathematics in Germany -- Supporting the Participation of Immigrant Learners in South Africa: Switching to Two Additional Languages -- Sect ion IV: Mathematics Teaching and Teacher Education in Multilingual Classrooms -- Operationalising Wenger’s Communities of Practice Theory for Use in Multilingual Mathematics Teacher Education Contexts -- Developing Mathematical Reasoning in English Second-Language Classrooms Based on Dialogic Practices: A Case Study -- Mathematics Teacher’s Language Practices in a Grade 4 Multilingual Class -- Complementary Functions of Learning Mathematics in Complementary Schools -- The Evolution of Mathematics Teaching in Mali and Congo-Brazzaville and the Issue of the Use of French or Local Languages.Contemporary concerns in mathematics education recognize that in the increasingly technological and globalized world, with concomitant change in population demographics (e.g. immigration, urbanization) and a change in the status of languages (e.g. English as a dominant language of science and technology) multilingualism in classrooms is a norm rather than an exception. Shifts in perspective also view language not simply as an instrument for cognition with all learners equipped with this instrument in service of learning, although clearly in the classroom that remains of importance. Rather, it is now also being acknowledged that language use is inherently political, so that the language that gets official recognition in the classroom is invariably the language of the powerful elite, or the dominant societal language, or in the case of post-colonial contexts the language of the colonisers. From this socio-political role of language in learning quite different issues arise for teaching, learning and curriculum for linguistically marginalized learners than that of cognition (e.g. immigrants, second language learners, other). Policies on language in education are being considered and re-considered with specific reference to mathematics teaching and learning. Given the policy environment, globally the proposed publication is timely. This edited collection draws on recent, emerging insights and understandings about the approaches to improving policy and practice in mathematics education and mathematics teacher education in multilingual settings. It presents, and discusses critically, examples of work from a range of contexts and uses these examples to draw out key issues for research in education in language diverse settings including teaching, learning, curriculum and fit these with appropriate policy and equity approaches. With contributions from all over the world, especially novice researchers in low income countries, this book is a valuable resource for courses in Mathematics Education and related social sciences both at the graduate and undergraduate levels, as well as for students of international development.