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
Pascalft s Law Apparatus, Weight: 3.3lb, Length: 13.0in, Width: 8.7in, Height: 9.4in, Consists of a moulded plastic base into top of which may be screwed one of a set of four vases of differing shape & a movable index on vertical rod enables the height of water