The Common Core State Standards Initiative is a voluntary program that establishes what K-12 students should learn in mathematics and English language arts by the time they complete each grade. As of 2015 forty-three states, the District of Columbia and four territories have adopted these standards for their schools.
A push for a national initiative began to develop in the 1990s, but would not begin to take its current form until 2009. The standards are licensed by the Council of Chief State School Officers through the Department of Education.
Common Core is not a law, and states are free to choose whether they will adopt it or not. Initially, almost all of the states adopted it, but some have since formerly withdrawn or had it repealed, such as Indiana, Oklahoma, South Carolina and Tennessee. At present only Alaska, Nebraska, Texas and Virginia have never adopted any of the standards.
The English standards cover reading, writing, speaking and listening, vocabulary, and media and technology. Math standards for grades K-5 include operations and algebraic thinking, number and operations in base 10, measurement and data, and geometry. Standards for the sixth to eighth grade include the number system, geometry, expressions and equations and statistics and probability. The standards are more flexible in the content of high school classes.