In this study we attempted to assess the affect of hands-on activity, one of the methods related to the discovery strategy, and to find out to what extent it affects the success of mathematics teaching. This is a piece of experimental research and its participants were the students of three different schools in the centre of Siirt. Data were collected and analyzed by the independet t test technique; its mean level was taken as 0.01. The results showed that the classes giving priority to the active contribution of the students and to hands-on activities showed greater success than those which applied traditional methods in teaching mathematics.