A spin off to Fulghum’s book (below) is that by high school, students have been presented with almost all of the math they need if they are not pursuing college.
High school math, aside from some exceptions, is largely designed to prepare students for college and subsequent careers.
If your student is entering high school and does not have a postsecondary goal of college (2 or 4 year) then you can turn the main focus of the math education to topics covered before high school.
Some of the topics in geometry and statistics are applicable to real life and most of those would have been covered in the Statistics or Geometry and Measurement domains from previous grades. There are topics unique to high school math that are prerequisites for some vocations, e.g., trigonometry for surveying. Some applications of the high school math address real life, but the focus is on the math and not the applications.
The image below shows a breakdown of a sample of topics for life skills math and for two vocations. Here is a link to a PDF of the document shown above. You can see the math topics. Here are the links to the pages for the plumbing topics and the welding topics.
Related to this value of college education for certain job sectors. The director of the Office of Higher Education in Connecticut, Tim Larson, stated that many companies have proprietary software, programs, or procedures that they will teach new hires. The take away from this is that much of the actionable knowledge needed would not be covered in college. Many of the skills they are looking for are not academic in nature. The Wall Street Journal published two articles that speak to the change in requirements for some jobs, in which a college degree is no longer a requirement (“Rethinking the Need for College Degrees“, “Is this the end of college as we know it?”)
A college education (or at least the degree) provides incredible opportunities, but it is not needed for many students.