This article looks at how teachers understand recent mathematics refor
ms. Case studies of three California teachers in a disadvantaged, urba
n elementary school are presented. Framing the study are issues of tea
cher learning and systemic reform. These teachers have access to multi
ple opportunities to learn about reforms. But access guarantees no com
mon understandings. Teachers' understandings are influenced by the kin
ds of students they have, their prior knowledge and experience, their
views of mathematics, textbooks and tests. If teachers understand refo
rms in different ways, this raises questions about systemic reform and
the notion of alignment. But there are other problems as well. Questi
ons about what it means to be aligned, how all students' needs might b
e considered, and what the multiple goals of a decentralized system me
an for teachers suggest that efforts at systemic reform will be challe
nged on several fronts.