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elementary school student; primary school student; grade school student
息子は来年から小学生になる予定です。
My son will become an elementary student next year.
小学生のころ野球をしていました。
I played baseball when I was in elementary school.
小学生のころ、毎日川で泳いでいた。
When I was in elementary school, I swam in the river every day.