From The New York Times Magazine:

This article explores the process of teaching and learning how to teach math in America. Tracing various teaching revolutions of the 1960s, 80s, and today, this piece argues that although these reforms have been well-intentioned, they often come without a system for helping teachers learn how to teach them. The article also compares the America system of teaching math teachers to the Japanese system in order to explore where the disconnect between educational theory and practice may be happening.