- Divisibility and the Division Algorithmages 18 to 19 · on the way
- Euclid's Algorithm and Bezout's Identityages 18 to 19 · on the way
- Modular Arithmetic and Congruence Classesages 19 to 20 · on the way
- Linear Congruences and the Chinese Remainder Theoremages 19 to 20 · on the way
- Fermat's Little Theorem and Euler's Theoremages 20 to 21 · on the way
- Primitive Roots and the Units Modulo nages 20 to 21 · on the way
- Quadratic Residues and the Law of Reciprocityages 21 to 22 · on the way
- The Distribution of Primes and What Is Still Openages 21 to 22 · on the way