K-12 education in the United States includes primary education starting in kindergarten, and secondary education ending in grade 12. Government-funded free schools are generally provided for these grades, but private schools and homeschooling are also possible. Most children begin elementary education with kindergarten (usually five to six years old) and finish secondary education with twelfth grade (usually 17–18 years old). In some cases, pupils may be promoted beyond the next regular grade. Parents may also choose to educate their own children at home; 1.7% of children are educated in this manner.
In 2010, American students ranked 17th in the world. The Organisation for Economic Co-operation and Development (OECD) says that this is due to focusing on the low end of performers. All of the recent gains have been made, deliberately, at the low end of the socioeconomic scale and among the lowest achievers.
About half of the states encourage schools to make their students recite the Pledge of Allegiance to the flag daily.
Transportation
Transporting students to and from school is a major concern for most school districts. School buses provide the largest mass transit program in the country, 8.8 billion trips per year. Non-school transit buses give 5.2 billion trips annually. Around 440,000 yellow school buses carry over 24 million students to and from schools. In 1971, the Supreme Court ruled unanimously that forced busing of students may be ordered to achieve racial desegregation. This ruling resulted in a white flight from the inner cities which largely diluted the intent of the order. This flight had other, non-educational ramifications as well. Integration took place in most schools, though de facto segregation often determined the composition of the student body. By the 1990s, most areas of the country had been released from mandatory busing.
School start times are computed with busing in mind. There are often three start times: for elementary, for middle and junior high school, and for high school. One school district computed its cost per bus (without the driver) at $20,575 annually. It assumed a model where the average driver drove 80 miles per day. A driver was presumed to cost $.62 per mile (1.6 km). Elementary schools started at 7:30 am, middle schools and junior high school started at 8:30, and high schools at 8:15. While elementary school started earlier, they also finish earlier, at 2:30 pm, middle schools at 3:30, and high schools at 3:20. All school districts establish their own times and means of transportation within guidelines set by their own states.
Grade placement
Schools use several methods to determine grade placement. One method involves placing students in a grade based on a child's birthday. Cut off dates based on the child's birthday determine placement in either a higher or lower grade level. For example, if the school's cut off date is September 1, and an incoming student's birthday is August 2, then this student would be placed in a higher grade level. If the student is in high school, this could mean that the student gets placed as an 11th grade instead of a 10th because of their birthday. The content each grade aligns with age and academic goals for the expected age of the students. Generally a student is expected to advance a grade each year K-12; however, if a student under-performs, he or she may retake that grade.
Primary education
Historically, in the United States, local public control (and private alternatives) have allowed for some variation in the organization of schools. Elementary school includes kindergarten through sixth grade (or sometimes, to fourth grade, fifth grade or eighth grade). Basic subjects are taught in elementary school, and students often remain in one classroom throughout the school day, except for specialized programs, such as physical education, library, music, and art classes. There are (as of 2001) about 3.6 million children in each grade in the United States.