This introduction provides all of the tools to achieve a solid foundation in number theory. It connects number theory to other branches of mathematics and to real-world problems, such as the ISBN system, RSA codes, and the construction of tournaments. Coverage of special topics includes elliptic curves and Hilbert’s tenth problem. The text uses Mathematica ® and Maple™ calculations to expand on the theory covered, features numerous worked examples and exercises, and provides a supplemental web page with Mathematica notebooks, Maple worksheets, and links to Internet resources. A solutions manual is available for qualifying instructors.