By state law, education is compulsory over an age range starting between five and eight and ending somewhere between ages sixteen and eighteen, depending on the state.^[11] This requirement can be satisfied in public schools, state-certified private schools, or an approved home school program. In most schools, compulsory education is divided into three levels: elementary school, middle or junior high school, and high school. Children are usually divided by age groups into grades, ranging from kindergarten (5- to 6-year-olds) and first grade (6- to 7-year-olds) for the youngest children, up to twelfth grade (17- to 18-year-olds) as the final year of high school.