Mathematics Education and Language Diversity : The 21st ICMI Study Introduction Challenges and opportunities for second language learners in undergraduate mathematics Mathematics in the hands of deaf learners and blind learners: visual gestural somatic means of doing and expressing Challenging deficit perspectives: student agency in multilingual mathematics classrooms Language diversity in mathematics teacher education: challenges across three countries Impact of differing grammatical structures in mathematics teaching and learning Addressing multi language diversity in mathematics teacher education programs Language diversity and new media: issues of multimodality and performance Making use of multiple (non shared) first languages: state and need of research and development in the European language context Purposefully relating multilingual registers building theory and teaching strategies for bilingual learners based on an integration of three traditions Trends in mathematics education in multilingual contexts for indigenous population: experiences from Latin America Tensions in teaching mathematics in contexts of language diversity Research rationalities and the construction of the deficient multilingual mathematics learner Language diversity in research and its consequences Using ICTs to facilitate multilingual mathematics teaching and learning Mathematics teaching language policy and the political role of language: perspectives from around the world Reflections Index. This book examines multiple facets of language diversity and mathematics education. It features renowned authors from around the world and explores the learning and teaching of mathematics in contexts that include multilingual classrooms indigenous education teacher education blind and deaf learners new media and tertiary education. Each chapter draws on research from two or more countries to illustrate important research findings theoretical developments and practical strategies. .