If you do send them to public school, make sure to tutor them either yourself or with a company.  For reading there are a lot of good phonics books you can use yourself.  Same for grammar and spelling.  For math you might want to go with an extracurricular program like Kumon or Spirit of Math.  Also you should inquire whether your local school has split grades.  Education theorists love them.   But in combination with mainstreaming of kids with behavioural problems, they create a chaotic elementary classroom where learning is difficult.  You don't need to go private if you have the time and resources to teach the essentials away from public school.  Though your children may still be victimized by mainstreamed kids.