Reasoning about graphical representations representing dynamic data (e.g., distance changing over time), including interpreting, creating, changing, combining, and comparing graphs, can be considered a domain-specific operationalization of the general twenty-first century skills of creative, critical thinking and solving problems. This paper…

This paper compares lessons on linear equations from the same curriculum materials taught by two teachers of different levels of mathematical knowledge for teaching (MKT). The analysis indicates that the mathematical quality of instruction in these two classrooms appears to be a function of differences in MKT. Although the two teachers were…

This instructional unit contains four classroom lessons dealing with energy for use in grades six and seven. The overall objective is to provide students with a comparative overview of two basic energy concepts: energy is a basic need in all cultures; and energy use affects the way people live. In the lessons, which can easily be integrated into…