This study contributes to the literature by examining in more detail the correlations among contextual factors defined by the teachers' technical confidence, lesson planning skills, and the extent of IWB usage in mathematics classroom discourse. The sample for the current study consisted of 134 elementary school teachers in grades K-5 using interactive whiteboards (IWB) with their math lessons. A questionnaire consisting of 17 items measured the teachers' perceptions related to their technical competency in using the IWB, skills in planning IWB-based lessons, and observations of students' engagement, behavior, and achievement based on using the IWB in mathematics classroom discourse. The findings suggest that teachers' technical confidence in using the IWB does matter with regard to planning IWB-based lessons and to engaging students in the classroom. The findings also suggest that the teachers' skills in planning IWB-based lessons matters to students' engagement and behavior in mathematics classroom discourse. Lastly, the findings recommend concurrent high use of the IWB among teacher and students in classroom discourse if the goal is to maximize IWB student effects.