Written for the one-term course, Essentials of Discrete Mathematics, Fourth Edition is designed to serve computer science and mathematics majors, as well as students from a wide range of disciplines. The mathematical material is organized around five types of thinking: logical, relational, recursive, quantitative, and analytical. This presentation results in a coherent outline that steadily builds upon mathematical sophistication. The final chapter, Thinking Through Applications, emphasizes the multidisciplinary approach of the text and contains case studies that integrate the fields of biology, sociology, linguistics, economics, and music. - New Activities: Each section in Chapters 1 through 5 now include new activities designed to be completed in class using inquiry-based learning - Previews: The former Inquiry problems have transitioned to Preview problems and have been revised to align with the new activities in the chapters. - Exercises: New and revised exercises are now found at the end of each chapter and identified by section. - Available with WebAssign Online Homework and Grading