Translation of "Elementary" in Chinese

I miss my elementary school teachers.

我很想念小學的老師。

They became friends in elementary school.

他們在小學時就是朋友了。

I went to elementary school in Nagoya.

我在名古屋读的小学。

When I was in elementary school, my mother always fetched me from school.

我读小学的时候，我母亲常常来接我。

The graduation from elementary school to middle school is regarded by some as the first step towards adulthood.

有些人認為從小學升到中學是踏入成年的第一步。

- This problem is too difficult for primary school children to solve.
- This problem is too difficult for elementary school children to solve.
- This problem is too difficult for grade school children to solve.

这个问题让小学生解决太难了。