The goal of this unique book is to provide the tools for readers to become active participants in carrying out their own investigations about curved spacetime near Earth and black holes. To that end, the book uses calculus and algebra, rather than tensors, to make general relativity accessible. Five chapters introduce basic theory and seven projects guide readers in the analysis of major applications. To facilitate study and review, each section begins with a summary of the key idea. Marginal notes highlight other important points.