Preface to the English Edition
Part 1. Continued Fractions
Continued Fractions
What is a Continued Fraction?
The Geometric Theory of Continued Fractions
Kuzmin's Theorem
Multidimensional Continued Fractions
A Generalization of Lagrange's Theorem
Editors' Comments
Part 2. Geometry of Complex Numbers, Quaternions,
and Spins
Geometry of Complex Numbers, Quaternions, and Spins
Complex Numbers
Motions of the Plane
A Digression Concerning Orientations
The Generalization of Complex Numbers to the Concept of
Quaternions
Some Examples
Newton's Differential Equation
From the Pythagorean Theorem to Riemann Surfaces
Mathematical Trinities
Spins and Braids
Appendix
Editors' Comments
Part 3. Euler Groups and Arithmetic of Geometric
Progressions
Euler Groups and Arithmetic of Geometric Progressions
1. Basic Definitions
2. A Digression on the Euler Function
3. Tables for Euler Groups
4. Euler Groups of Products
5. The Homomorphism Given by Reduction Modulo a, F(ab) --+ F(a)
6. Proofs of the Theorems on Euler Groups
7. Fermat-Euler Dynamical Systems
8. Statistics of Geometric Progressions
9. Measurement of the Degree of Randomness of a Subset
10. The Average Value of the Parameter of Randomness
11. Additional Remarks about Fermat-Euler Dynamics
12. Primitive Roots of a Prime Modulus
13. Patterns in Coordinates of Quadratic Residues
14. Applications to Quadratic Congruences
Part 4. Problems for Children 5 to 15 Years Old
Problems
Solutions to Selected Problems
Bibliography