How young is 'grade school'? How old is 'kindergarten'?

Language English Grammar & Usage
1

Looking idly through the teaching jobs offered section of the classifieds, I find jobs offered for both kindergarten and ‘grade school’. At what point does kindergarten end and grade school start? If it’s illegal to teach older kindy kids, is it also illegal to teach younger grade school kids?

2

I think 3- 6 years old is kindergarten age.

[quote]If it’s illegal to teach older kindy kids, is it also illegal to teach younger grade school kids?
[/quote]
It’s legal but buxiban can accept students under 3 years old

3

Thanks. In Australia you start gradeschool at 5 years of age.