By playing with toys, children sometimes wonder how and why toys do what they do. At the moment of curiosity, interest can be captured and thinking can be influenced. This is a good time to focus on natural phenomena, provoke imagination, and promote scientific thinking. This book presents 53 classroom-tested activities to teach science with toys. Each activity has two components: (1) the science content to be understood; and (2) the "sciencing" of the activity--children doing, recording, expressing ideas, verifying ideas, participating in further investigations, working with others, etc. The activities in the book contain the following information: Focus, Challenge, Materials, Resources, Safety Note, Advance Preparation, Time, Procedure, Further Challenges, and References. This book also contains a bibliography of books for teachers and tips for inventing and designing toys. (PR)