The activity was suitable for children in the same age group.
grade level
Frequency:
60
%
Students in the same grade level often take similar classes.
classmates
Frequency:
50
%
Her classmates organized a surprise party for her birthday.
Idiomatic Expressions for year group
Phrase: skip a year group
Meaning: to advance to a higher academic year or grade level without completing the previous one
Usage: He is so smart that he skipped a year group in school.