It's really too bad that high schools do not teach basic accounting, compound interest, and how the free market system works.

Things people need to know to function in our society.

There is no "free market system" here. There's an organised debt slavery racket run for the benefit of parasitic rent-seekers who operate with federal sanction.

College loans have taken point on this for the aspiring middle classes. In a very literal sense this system is the exact opposite of genuine freedom and opportunity.

In high school I took economics, precalculus (which taught exponential growth), and history (which talked about financial crises of the past). The information was taught, but the problem is that there was no class to tie this information into life practice.

How does the free market system work?

Isn't that then a gigantic failure of high school then? If there is one thing we need to prepare students for, isn't it how to start making career decisions?

If that's a goal of high school, then yes, it's a huge failing. There's also a bunch of other useful stuff they don't teach you, like cooking and how to wash your clothes. There's no coherent idea of what school is supposed to be, though. Is it a place to learn a bunch of practical skills? Or a place to read about some interesting ideas? All those things take time and money, and we end up with a school that does a bunch of different stuff with no real plan.

Our town used to have the Mechanics' Academy. A 12-week study program to learn enough math to balance, books, amortize a loan, calculate weights and measures, figure load limits. Graduates were very employable. My Mom's Grandfather was one.

Long ago demolished and turned into a Mall during Urban Renewal.