Topics: Game theory, decision theory, econometrics, statistics
1 - For those interested in statistical methods, Green's "Econometric Analysis" (2018 and prior editions) has an accessible Part 1 on "The Linear Regression Model" and a lovely conceptual foundations appendices in Part IV in linear algebra, distribution theory, estimation and inference, and some optimization methods.
Although this is technically a graduate level text, there's nothing mystifying about it with a calculus background. The appendices would be an excellent, tightly-delivered read for an ambitious, math-oriented high schooler who has completed AP calculus. It's used in quant-heavy undergrad fourth year classes dual-enrolled with grad studies, so I say undergrad level.
2 - Students interested in an introductory, axiomatic/proof-based treatment of game theory, asset markets, and optimizations will enjoy Hal Varian's "Microeconomic Analysis" (3rd edition, 1992).
Again - this is technically marketed as a first-year graduate text, but I know it as a third-year undergrad text. High schoolers in our families with a taste for economic optimization and intro game theory will enjoy this.
3 - And finally...for the aspiring game or decision theorist, R. Duncan Luce's 1989 "Games and Decisions: Introduction and Critical Theory" is a cute treatment of the topic for undergrads. (I promise! This book is actually recognized as for undergrads!)
Order of operations here is:
Appendices in 1
3
Part 1 of 1
2
Rest of 1 ad libitum