Guiding preservice teachers in developing TPCK

Two hundred years ago, the predominant belief about preparing teachers for teaching was that knowing the content at a particular level was adequate preparation for teaching that content at that level. Teachers needed to know and understand the content determined by the grade they planned to teach. An elementary reading teacher needed to be able to read, write, and compute at the elementary level. At the secondary level, a geography teacher needed a secondary level geography understanding and a mathematics teacher needed a secondary level mathematical understanding. Teachers taught what they were taught, as they were taught. That was yesterday.