Vibration generator for exciting oscillating and waves mechanically, e.g. in coil springs, a rubber cord, a wire ring or a Chladni plate. In robust plastic housing including mounting pin with 4-mm socket for attaching accessories
Number, Measurement and Space, module establishes equivalence of sets by a one-to-one exchange of objects. Eg Upsetting equivalance (destroying conservation of numbers) by adding one object to a set, or taking one away, helps introduce vocabulary for comparing quantity