ABSTRACT
This chapter deals with several fundamental topics from elementary number theory. It discusses the notion of divisibility of integers. The chapter states two extremely important results about positive integers. These results are known as the division and Euclidean algorithms, respectively. The Euclidean algorithm provides a very systematic and efficient way to calculate greatest common divisor. Prime numbers are the building blocks of the integers. The chapter identifies how the primes serve as the “building blocks” of the integers. Euclid theorem provides the foundation for the truly important role that the primes play in elementary number theory. The chapter also discusses how to find the solutions for linear congruence and proves the Euler and Fermet theorems.
