My Random Wish List of Unfinished Topics

1. The set of rational numbers is countable.
2. Farey sequences, approximation, and continued fractions.
3. Relationship of rational numbers to chords and musical scales.
4. The set of real numbers is uncountable.
5. Existence of irrationals.
6. Computing square roots.
7. Geometric interpretation of addition and multiplication of complex numbers.
8. Roots and powers of complex numbers.
9. Defining the Mandelbrot set.