In this second issue of Mathematics for the 3rd Grade, we complete Algebra with the chapter on systems of two equations with two unknowns. Then, with the introduction to probability theory, we come into contact with sets, the universal language of Mathematics. The probabilities themselves will allow us to give a clearer meaning to phrases we use daily, including words like "may," "perhaps," and "possibly."

The Geometry section includes the study of equality and similarity of plane figures, based on the equality and similarity of triangles. The study of these concepts will allow us to delve deeply into the process of proof, that is, the logical process that distinguishes Mathematics from all other branches of science.

Finally, we will generalize our knowledge in Trigonometry, perhaps the most practical tool that Mathematics offers to culture.

The issue concludes with a systematic preparation for final exams. There, the graduating student of the Gymnasium and -a few months later- the candidate for the 1st Lyceum will find everything they need to organize, summarize, and check the necessary knowledge for both their success in exams and their smooth progress in high school.

(from the authors' preface)