Classroom-tested and with a flexible format, Introduction to Number Theory presents a modern treatment of special topics in number theory, including elliptic curves and decision algorithms for Diophantine equations. The text places an emphasis on making connections between various branches of mathematics-including combinatorics, algebra, and analysis-to real-world problems such as the ISBN system, RSA codes, and the construction of tournaments. In addition to containing a comprehensive appendix on its use, the text provides coverage of both Mathematica? and Maple? to illustrate and to expand on the mathematical theories. A supporting website features references and Mathematica and Maple notebooks.