I have written an outline of one possible version of the foundational topics of secondary school math, covering key concepts usually taught in grades 7 to 10. The idea was to write a one-year review course for seniors who have had trouble with math up to that point, but still intend to go to a two-year college.
I tried to incorporate the input I received from teachers at two-year colleges, as well as my own sense of what is at the same time important, accessible, and interesting.
I am hoping the course outline (entitled "Mathematics Overview") will be useful to a broader audience, in addition to the one mentioned above. For example, it could be used in two-year colleges. Or it could be stretched out over two years, and serve as the skeleton of a middle school curriculum. Or it could be used by any secondary school teacher as a guide to a different approach to use when teaching various topics, instead of —or in addition to— what they would otherwise do.
The outline is available here for download.