The Council of Chief State School Officers (CCSSO) and the National Governors Association Center for Best Practices (NGA Center) have developed K-12 Common Core State Standards documents on behalf of 48 states, two territories, and the District of Columbia. These English language arts and mathematics standards represent a set of expectations for student knowledge and skills that high school graduates need to master to succeed in college and careers. To develop these standards, a wide range of educators, content experts, researchers, national organizations, and community groups worked together. These final standards reflect the invaluable feedback from the general public, teachers, parents, business leaders, states, and content area experts and are informed by the standards of other high performing nations.