This practice brief provides educators with current research findings and evidence-based, high quality, instructional mathematics' practices from the Institute of Education Sciences' Practice Guide for teaching English learners (ELs) academic content, and highlights instructional practices used to teach ELs according to the National Academies of Science, Engineering, and Medicine, which may be helpful in explaining how research findings can be incorporated into classroom practice. This brief provides teacher educators with the latest research on how to better prepare the next generation of teachers. Five key teacher educator and leader practices featured include: (1) Embrace asset beliefs that position and support ELs as full participants in mathematical learning; (2) Engage ELs in meaningful interactions and discourse with others; (3) Provide support for ELs to engage in mathematical practices; (4) Sustain an explicit focus on language as it is used in math; and (5) Design mathematical learning experiences that engage ELs in rich communications integrating oral and written language. For each key practice, this brief describes and references the research, illustrates the practice in action, and offers additional tools and resources.