Here follows a brief review of the second edition of this book (for a detailed review of the first edition, see Newsletter issue 38). The aim of this well-written book is to fill the gap between high-school mathematics and mathematics at university. The author shows to the reader what it means to prove something rigorously. The book includes sections about number systems, combinatorics and geometry, and gives a basic introduction to analysis and set theory. The second edition contains more exercises and new chapters about RSA codes and permutations.