The ubiquitousness and robustness of traditional practices in the teac
hing of school mathematics raise two fundamental and interrelated ques
tions: Will the fate of the current reform effort in mathematics educa
tion be any different from that of previous reform efforts? Why have t
hese traditional practices been so constant and durable? Certainly the
se are questions that cannot be answered in a single study. However, i
n an effort to develop a research basis that could aid in thinking abo
ut these questions, I conducted an ethnographic case study of a beginn
ing high school mathematics teacher's acculturation into the school ma
thematics tradition (i.e., the beliefs and practices that characterize
the traditional approach to school mathematics). The analysis present
ed here focuses on the tensions and contradictions that underlie the b
eliefs and practices of the school mathematics tradition and on the wa
ys that teachers cope with these tensions and contradictions. It also
indicates how the explanations and strategies that teachers employ to
cope with these tensions and contradictions on actually help to sustai
n the tradition.