Thoroughly revised and updated, the new Second Edition of Neville Robbins' Beginning Number Theory includes all of the major topics covered in a classic Number Theory course and blends in numerous applications and specialized treatments of number theory, including Cryptology, Fibonacci numbers, and Computational Number Theory. The text strikes a balance between traditional and algorithmic approaches to elementary number theory and is supported with numerous exercises, applications, and case studies throughout. Computer exercises for CAS systems are also included.