Pure Mathematics for Beginners consists of a series of lessons in Logic, Set Theory, Abstract Algebra, Number Theory, Real Analysis, Topology, Complex Analysis, and Linear Algebra.
Lesson 4 from this series focuses on properties of the integers. In this lesson we will learn about rings (and the integers in particular), divisibility, and mathematical induction.
Although the content in this lesson is mostly self-contained, the author recommends covering Lessons 2 and 3 before this one. In particular, the basic proofwriting skills taught in Lesson 2 will be useful, and knowledge of the definitions introduced in Lessons 2 and 3 will be helpful.