• Assorted sponges
• Water resistant glue, such as Elmer's Stix
Cut the sponges into geometrical shapes. Involve your child in deciding which pieces to use to build interesting shapes, such as boats, ice cream cones, a house, etc. Glue the pieces together. Let the glue dry completely before playing with the shapes in the bathtub.
Source: Excerpted from 365 Days of Creative Play by Sheila Ellison & Judith Gray (Sourcebooks, 1995)