This book, which is the second volume of the work entitled "Mathematics for the Positive Direction of the 2nd grade of the Lyceum", contains Number Theory, in the context of the new syllabus provided for this grade (1992-1993 ).

It is divided into six chapters. In each chapter, the relevant theory is briefly developed and the necessary methodology for solving the exercises is clearly presented. At the end of each chapter there is a large number of solved exercises. After the 6th chapter there are general solved exercises and an appendix of solved problems.

  Emphasis is placed on exercises unknown in the Greek literature and on subjects of various exams and competitions (French Baccalaureate , exams of the Universities of Cambridge , London , Oxford , Moscow , Bucharest , etc., G. Putnam competition, Olympiad competitions, E.M.E competitions . etc.).