This paper explores how the RepTools toolkit was appropriated in two different classroom cultures. The RepTools toolkit consists of hypermedia about a complex system, physical models, and NetLogo simulations, designed to help students understand complex systems in the context of aquarium ecosystem. This paper reports on the nature of the different enactments of two teachers using the same tools. Although both classrooms showed similar learning gains, Interactions Analyses (IA) found differences between the enactments in two main areas; (1) providing opportunities for inquiry and language used to communicate and (2) teacher interpretation of the computer model. These findings suggest that how tools are appropriated is greatly influenced by teacher beliefs and classroom culture and that there may be multiple paths to productive use of such tools.