Children and adolescents who come to Germany have very different prior knowledge of our writing system and numeral system. "Mathematics for Children of Non-German Origin" takes this into account and introduces them to German school mathematics in a differentiated manner. The workbooks enable children and adolescents from all backgrounds to connect with mathematics lessons. The technical terms, especially numbers and number words, are introduced and continuously interconnected. The predominant calculation methods in Germany are demonstrated and practiced. Common forms of representation and tools are presented, and their use is practiced. Typical task formats from German textbooks are introduced and worked on. Fluent number processing is a fundamental prerequisite for success in a foreign language mathematical environment. Only the new terms.