noun
single-grade classroom; single-grade class
Used in educational contexts to refer to a classroom or class consisting of a single grade level, as opposed to a combined or multi-grade class.
この学校では、単級の授業が基本です。
At this school, single-grade classes are the norm.
複式学級ではなく、単級での指導を希望する。
I prefer instruction in a single-grade classroom rather than a combined class.