For thousands of years before the invention of reliable clocks, humans measured their days by the motion of the sun. Astronomically, one day was the length of time it took for the sun to return to the same position in the sky. With the advent of precise mechanical chronometers such as Harrison's timekeepers (Sobel and Andrewes 1998), which ran at…

The purpose of this qualitative case study was to examine the modeling of technology by mathematics professors in two universities in teaching required courses for secondary level pre-service mathematics teachers. Six professors participated in this case study. Their responses were documented in pre- and post-interviews and data were gathered from…