The National Academy of Education (NAEd) Civic Reasoning and Discourse project aims to support civic reasoning and discourse in the schools by helping teachers across disciplines to prepare youth in the United States to examine and discuss complex issues in ways that are thoughtful, developmentally appropriate, and respectful of others' opinions and experiences. In mathematics, this can mean mathematizing issues that are meaningful and relevant to students' lives--issues that may be related to current curricular topics (e.g., aspects of "fairness") or that are not dealt with in many curricula (e.g., making decisions regarding safe social practices during a pandemic or addressing some of the issues involved in voting rights). Addressing complex topics such as these calls for conceptualizing and representing relevant phenomena; making clear claims; specifying assumptions; supporting justifications with evidence; weighing multiple points of view; and then working through such assumptions, claims, and rationales with others to construct and critique viable arguments. The curriculum materials that historically have dominated the mathematics textbook market in the United States have provided little support for dealing with current or complex issues, either in terms of content or pedagogy. This report offers such support. It provides background information regarding teaching and learning mathematics, which undergirds powerful classrooms--classrooms from which students emerge as agentive and mathematically, epistemologically, and socially powerful thinkers. It offers a set of principles for powerful pedagogy and practice in mathematics, describing what teachers can offer to ensure that every student is enfranchised and supported equitably in thinking, learning, and acting in the world. It briefly describes three curricular strands connected to current civic issues (fairness, environmental justice, and social justice) that can be addressed with increasing developmental, social, and mathematical sophistication through the grades. It identifies specific developmental considerations for students at the elementary, middle, and secondary grade levels. It then focuses on specifics related to students' mathematical thinking, development, and learning, along with annotated curricular examples for each of the three strands. The final section of the report addresses next steps. It offers suggestions for professional development to help make these ideas a reality, and thoughts about possible research and development.