Stephanie Bücherl presents an empirical reconstruction of controlling practices, drawing on a data set obtained through participant observation in the finance headquarters of a global corporation. The claim of controlling-based corporate management for objectivity and rationality is confronted with empirical reality. The study provides solid evidence that the discrepancy between claim and reality does not occur by chance, but is rather a systematic result of the embedding of controlling in organizational structures and processes. The author details the techniques and mechanisms through which controlling maintains the myth of number-based objectivity and rationality.