This is the 3080th most frequent Japanese word.
中学年
"Middle grades" (typically 3rd and 4th grade in elementary school).
In this sentence, '中学年' is used to refer to students belonging to middle-grade levels within an educational system, typically grades 3 to 4 in elementary school, depending on the country's educational setting.
彼の兄は中学年のクラスの担任です。
His older brother is a homeroom teacher for a middle-grade class.
Here, '中学年' describes a stage in educational progression, highlighting the phase when students might experience curricular changes or additions.
中学年になると新しい科目を学び始めます。
By middle grades, students start learning new subjects.
The usage '中学年' in this context pertains to designing activities or educational experiences tailored specifically for students in the middle-grade category.