In this paper we examine how two groups of middle school students arrive at shared understandings of and solutions to mathematical problems. Our data consists of logs of student participation in the Virtual Math Teams (VMT) system as they work on math problems. The project supports interaction both through chat and through a virtual whiteboard. We have examined in detail, the sequential work these students do to constitute and specify "the problem" on which they are working in the ways they produce whiteboard objects and text postings. Solutions emerge as students come to understand the problem on which they are working. This understanding is achieved through gradual respecification of the math problem on which they are working.