Written by a distinguished mathematician and teacher, this undergraduate text uses a combinatorial approach to accommodate both math majors and liberal arts students. In addition to covering the basics of number theory, it offers an outstanding introduction to partitions, plus chapters on multiplicativity-divisibility, quadratic congruences, additivity, and more. Although mathematics majors are usually conversant with number theory by the time they have completed a course in abstract algebra, other undergraduates, especially those in education and the liberal arts, often need a more basic introduction to the topic. In this book, the author solves the problem of maintaining the interest of students at both levels by offering a combinatorial approach to elementary number theory. Among the topics covered in this accessible, carefully designed introduction are: Multiplicativity-divisibility, including the fundamental theorem of arithmetic Combinatorial and computational number theory Congruences, arithmetic functions, primitive roots and prime numbers Later chapters offer lucid treatments of quadratic congruences, additivity (including partition theory), and geometric number theory Of particular importance in this text is the author’s emphasis on the value of numerical examples in number theory and the role of computers in obtaining such examples. Exercises provide opportunities for constructing numerical tables with or without a computer. Students can then derive conjectures from such numerical tables, after which relevant theorems will seem natural and well-motivated. Dover is widely recognized for a magnificent mathematics list featuring such world-class theorists as Paul J. Cohen (Set Theory and the Continuum Hypothesis), Alfred Tarski (Undecidable Theories), Gary Chartrand (Introductory Graph Theory), Hermann Weyl (The Concept of a Riemann Surface), Shlomo Sternberg (Dynamical Systems), and multiple works by C. R. Wylie in geometry, plus Stanley J. Farlow’s Partial Differential Equations for Scientists and Engineers.