The education system in the United States is controlled by state and local governments. But education laws are similar in each state. For example, in all 50 states and 6 territories, all children must attend school from the age of 6 or 7 to the age of 16. Public schools are free of charge for grades 1 through 12. Private schools also operate in all states and territories. Some private schools are operated by churches and religious groups. Other private schools are not linked to any religious organization. Private schools must be approved by the state in which they operate. Most private schools do not receive government money. The parents of private school students pay the school. The school year usually begins in September and continues until June. Most states require a school year of 180 days. Some schools have changed this schedule and require students to attend school throughout the year.