
1. Infinity of primes 2. Arbitrarily long sequences of successive integers, all not primes 3. Number of primes between 1 and n 4. Euler’s formula yields primes for x=0,1,2,3,…39 5. Irrational numbers: Algebraic, Transcendental (transcends operations of ordinary arithmetic) 6. Irrationality of square root of 2 7. Covering intervals 8. Euler’s constant C: 9. Approximating irrationals by rational numbers 10. Cantor’s existence proof of transcendental numbers 11. Non-constructibility of cube root of 2 12. Impossibility of finding center of circle with straightedge alone 13. Impossibility of covering modified chessboard with dominoes 14. Impossibility of decomposing cube into smaller cubes all of different size 15. Sperner’s Lemma: enumeration of patterns, fixed-point theorem follows 16. 292 ways of changing a dollar 17. The number system 18. The number of ways of partitioning a number into sums 19. The number of ways of partitioning a number into squares 20. Coin tossing: probability of m heads in n tosses 21. DeMoivre - Laplace Theorem 22. Axioms of probability theory equivalent to axioms of measure theory 23. Independent events implies normal distribution 24. Permutation group and solution of algebraic equations 25. Group of residues modulo p, Wilson’s Theorem 26. Homology group (a factor group) 27. Vectors, matrices, and geometry 28. Special theory of relativity as an example of geometric view in physics 29. Transformations, flows, and ergodicity 30.
Mathematics, Form and Function by Saunders Mac Lane (1986 Springer-Verlag hardcover, ISBN 0-387-96217-4) [2]
[1]: https://www.cut-the-knot.org/books/kac/index.shtml
[2]: https://en.wikipedia.org/wiki/Mathematics,_Form_and_Function
Edit: In particular they showed on pages 58-60, without using jargon, how the idea of permutations leads to Cardano's formulas for the cubic.