Principles and Standards for School Mathematics (PSSM) are guidelines produced by the National Council of Teachers of Mathematics (NCTM) in 2000, setting forth recommendations for mathematics educators. They form a national vision for preschool through twelfth grade mathematics education in the US and Canada. It is the primary model for standards-based mathematics. The NCTM employed a consensus process that involved classroom teachers, mathematicians, and educational researchers. The resulting document sets forth a set of six principles (Equity, Curriculum, Teaching, Learning, Assessment, and Technology) that describe NCTM's recommended framework for mathematics programs, and ten general strands or standards that cut across the school mathematics curriculum. These strands are divided into mathematics content (Number and Operations, Algebra, Geometry, Measurement, and Data Analysis and Probability) and processes (Problem Solving, Reasoning and Proof, Communication, Connections, and Representation). Specific expectations for student learning are described for ranges of grades (preschool to 2, 3 to 5, 6 to 8, and 9 to 12). Origins The Principles and Standards for School Mathematics was developed by the NCTM. The NCTM's stated intent was to improve mathematics education. The contents were based on surveys of existing curriculum materials, curricula and policies from many countries, educational research publications, and government agencies such as the U.S. National Science Foundation. The original draft was widely reviewed at the end of 1998 and revised in response to hundreds of suggestions from teachers. The PSSM is intended to be "a single resource that can be used to improve mathematics curricula, teaching, and assessment." The latest update was published in 2000. The PSSM is available as a book, and in hypertext format on the NCTM web site. The PSSM replaces three prior publications by NCTM: Curriculum and Evaluation Standards for School Mathematics (1989), which was the first such publication by an independent professional organization instead of a government agency and outlined what students should learn and how to measure their learning. Professional Standards for Teaching Mathematics (1991), which added information about best practices for teaching mathematics. Assessment Standards for School Mathematics (1995), which focused on the use of accurate assessment methods. Six principles Equity: The NCTM standards for equity, as outlined in the PSSM, encourage equal access to mathematics for all students, "especially students who are poor, not native speakers of English, disabled, female, or members of minority groups." The PSSM makes explicit the goal that all students should learn higher level mathematics, particularly underserved