Math Acceleration

Julie Mack of the Kalamazoo Gazette refers us to a Washington Post story regarding math acceleration. After reading the article I wonder when is it most appropriate for students to learn arithmetic, algebra, geometry, statistics, trigonometry, or calculus?

I suspect that you might answer this question differently based on your description of what arithmetic, algebra, geometry, statistics, trigonometry, and calculus are. Within these subjects are a range of skills and concepts that are accessible across a wide range of students.