Materials and activities intended to teach mathematics for understanding were infused with traditional messages about Mrs. 0 certainly shared the framework's view in this matter, but it is one thing to embrace a doctrine of instruction, and quite another to weave it into one's practice. For even a rather monotonous practice of teaching comprises many different threads. Hence any new instructional thread must somehow be related to many others already there. Like reweaving fabric, this social and intellectual reweaving can be done in different ways. The new thread can simply be dropped onto the fabric, and everything else left as is. Or new threads may be somehow woven into the fabric. If so, some alteration in the relations among threads will be required. Some of the existing threads might have to be adjusted in some way, or even pulled out and replaced. If one views Mrs. 0's work from the perspective of the framework, new threads were introduced, but old threads were not pulled out. The old and new lay side by side, and so the fabric of instruction was different. However, there seemed to be little mutual adjustment among new and old threads. Mrs. 0 used the novel concrete materials and physical activities, but used them in an unchanged pedagogical surrounding. Consequently the new material seemed to take on different meaning from its circumstances what mathematics was, and what it meant to understand it.