Several AFT American Educator articles on Teaching Mathematics:

• Ron Aharoni: Helping Children Learn Mathematics
  

  A professional mathematician shares his insights about effective instructional practice, how children learn, the importance of a coherent, systematic curriculum—and mathematics—after taking up the challenge of teaching in an Israeli elementary school.

• Knowing Mathematics for Teaching:
  

  There is general agreement that teachers’ knowledge of the mathematical content to be taught is the cornerstone of effective mathematics instruction. But the actual extent and nature of the mathematical knowledge teachers need remains a matter of controversy. A new program of research into what it means to know mathematics for teaching—and how that knowledge relates to student achievement—may help provide some answers.