Teachers frequently encounter students with learned helplessness who are discouraged, turned off, or have given up trying to learn mathematics. Although learned helplessness has a long history in psychology, there has been no reliable means by which mathematics teachers can identify students exhibiting these debilitating yet changeable characteristic behaviours in the classroom. The psychometrically robust Rasch calibrated "Student Behaviour Scale" consisting of ten items rated on a five point scale provides teachers with an efficient interval measure of student learned helplessness and an ordered hierarchy of these behaviours as they are manifest in mathematics classrooms. (Contains 3 tables and 1 figure.)