The use of technology in elementary mathematics instruction tends to be low-level, despite its affordance of supporting the development of students' high-level reasoning ability. This study builds upon a sociocultural view of learning and was designed to determine what effect a technology-mediated dialogic learning intervention has on third-grade students' mathematical problem-solving ability as well as the quality of their mathematical talk. Using a pretest-posttest quasi-experimental design, the treatment condition used the VoiceThread iPad app to mediate small group discussion of word problem solving solution strategies, while students in the control condition participated in traditional teacher-directed mathematics instruction. Students in the treatment condition performed as well as the control condition on the posttest, but had significantly better quality mathematical discussions in response to the intervention.