This study examines the communication between pre-service teachers and sixth grade students in a project in which email was used for communication as students learned about fractions and were supported by the pre-service teachers. Specifically, the study investigated how the pre-service teachers applied their mathematical knowledge to understand children's mathematical responses and challenged those responses and mathematical ideas. Each of the 27 pre-service teachers sent 7 to 24 reply e-mails to their sixth grade partners. Those e-mails were examined and a two-way continuum emerged in terms of how they used the voice of the discipline and their disposition to the child's voice in their response e-mails. (Contains 1 figure.)