This book is number 2 of a series of elementary science books that presents a wealth of ideas for science activities for the elementary school teacher. Each activity includes a standard set of information designed to help teachers determine the activity's appropriateness for their students, plan its implementation, and help children focus on a range of exciting and relevant learning experiences. Information accompanying each activity includes developmental level, group size, key experiences, and notes to teachers. Case studies in implementing science activities with groups of students follow specific activities. This volume is divided into 11 parts: (1) "Triangles"; (2) "Structures Around Us"; (3) "Structures for Fastening"; (4) "Natural Structures and Forms"; (5) "Structure, Size, Symmetry, and Shape"; (6) "Structure and Patterns"; (7) "The Structural Properties of Materials"; (8) "Skin: A Living Structure"; (9) "The Structure of Everyday Items in the Science Context; (10) "Common Textbook Topics on Structure from a New Perspective"; and (11) "Structure and Form Case Studies: Some Classroom Experiences". Appendices contain teaching aids including communication techniques for the classroom, materials and equipment, measurement in science, testing and analysis, and safety and science and the development of problem solving skills. (JRH)