- Michael Bailey
Virtual manipulatives focus and constrain student attention on mathematical objects and processes (Moyer-Packenham & Westenskow, 2013). Properly designed virtual manipulative limit users to interactions that make its mathematical properties explicate. By illuminating the important properties, students are then able to form generalizations and abstraction (Moyer-Packenham & Westenskow, 2013; Durmus, Karakirik, & Baysal, 2006).
Upon opening the manipulative, students' attention is constrained to the measure of the angles of the triangle because it's really the only thing happening. Toggling the "Angle Sum" button then focuses their attention on the relationship between the angles and toggling the "Auxiliary Line" button focuses them on why the relationship hold true.