This is the 2572nd most frequent Japanese word.
小中学校
Elementary and middle school.
Here, "小中学校" is used to collectively refer to elementary (小学校) and junior high schools (中学校), describing the context of the educational environment.
小中学校での教育は子供の基礎学力を養うために重要です。
Education at elementary and junior high schools is essential for developing children's fundamental academic skills.
In this sentence, "小中学校" emphasizes the extracurricular activities commonly found within both elementary and junior high school settings.
多くの小中学校で部活動がさかんに行われています。
Club activities are actively conducted in many elementary and junior high schools.
Here, "小中学校" reflects the personal educational background, specifying that the individual attended both levels of schooling in their local area.