Secondary education in Japan is split into junior high schools (中学校 chūgakkō), which cover the seventh through ninth grade, and senior high schools (高等学校 kōtōgakkō, abbreviated to 高校 kōkō), which mostly cover grades ten through twelve. Lower-secondary schools cover grades seven, eight, and nine. Ages are roughly 13-15 with increased focus on academic studies. Although it is possible to leave the formal education system after completing lower secondary school and find employment, fewer than 4% did so by the late 1980s. Most junior high schools in the 1980s were government-funded public schools; 5% were private schools. At ¥552,592 (934 USD). The minimum number of school days in a year is 210 in Japan, compared to 180 in the United States. A significant part of the school calendar is taken up by non-academic events such as sports days and school trips. Teachers often majored in the subjects they taught. Each class is assigned a homeroom teacher who doubles as counselor. Unlike elementary students, junior high school students have different teachers for different subjects. The subject teachers usually move to a new room for each 50-minute period. Usually, students' lunch is provided by the school itself. Instruction tends to rely on the lecture method. Teachers also use other media, such as television and radio, and there is some laboratory work. By 1989 about 45% of all public lower-secondary schools had computers, including schools that used them only for administrative purposes. Classroom organization is still based on small work groups, although no longer for reasons of discipline. Students are expected to have mastered daily routines and acceptable behavior. All course contents are specified in the Course of Study for Lower-Secondary Schools. Some subjects, such as Japanese language and mathematics, are coordinated with the elementary curriculum.