This paper provides a glimpse into the positive effect on student learning as a result of empowering a classroom teacher of 20 years (Andrea) with subject matter knowledge relevant to developing fraction understanding. Having a facility with fractions is essential for life skills in any society, whether metricated or non-metricated, and yet students the world over are failing in this aspect of mathematics (Queensland Studies Authority, 2002; TIMSS, 1997). Understanding fractions requires comprehension and coordination of several powerful mathematical processes (e.g., unitising, reunitising, and multiplicative relationships) (Baturo, 1997, 2000). While this paper will report on student learning outcomes, its major focus is to tell Andrea's story and from this to draw implications for pre-service education and teaching. A section on Cognitive Diagnostic Common Fractions Test is appended. (Contains 2 tables and 2 figures.) [For complete proceedings, see ED489632.]