Yet the framework's mathematical exhortations were general; it offered few specifics about how teachers might respond, and left room for many different responses. Mrs. 0 used the new materials, but conducted the entire exercise in a thoroughly traditional fashion. The class worked as though the lesson were a drill, reciting in response to the teacher's queries. Students' sentences were accepted if correct, and written down on the board. They were turned down if incorrect, and not written on the board. Right answers were not explained, and wrong answers were treated as unreal. The framework makes no such distinction. To the contrary, it argues that understanding how to arrive at answers is an essential part of helping students to figure out how mathematics works-perhaps more important than whether the answers are right or wrong. The framework criticizes the usual memorized, algorithmic approach to mathematics, and the usual search for the right answer. It calls for class discussion of problems and problem solving as an important part of figuring out mathematical relationships (CSDE, 1985, pp. 13-14). But no one in Ms. 0's class was asked to explain their proposed number sentences, correct or incorrect. No student was invited to demonstrate how he or she knew whether a sentence was correct or not. The teacher used a new mathematics curriculum, but used it in a way that conveyed a sense of mathematics as a fixed body of right answers, rather than as a field of inquiry in which people figure out quantitative relations. It is easy to see the framework's ideas in Mrs. 0's classroom, but it also is easy to see many points of opposition between the new policy and Mrs. 0's approach (CSDE, 1987, p. 9).