@b05df304 @134318c2 @97401183  I think that "banned" is the wrong term to uses in most school districts. They simply lack the capacity to teach advanced math, including Calculus, even if they thought it was important and wanted to do so.  Starting with early grades, they think of math as a series of  drills to be memorized.  Who would teach the needed abstract reasoning concepts?

It is the lefty liberal districts, that do have some math capable teachers who do actually ban access to higher level math. They do so because they are worried about "gaps", the early sorting of students into high and low math tracks, a practice that disproportionately disadvantaged Black and Latino students and made it harder for them to access advanced courses down the line.  If you prohibit Algebra until 9th grade, some students are either getting outside supplementation, or they are being slowed down. Opportunities to burst forward are also not accessible.   https://www.edweek.org/teaching-learning/san-francisco-insisted-on-algebra-in-9th-grade-did-it-improve-equity/2023/03

Of course the issue isn't just school sorting, it is social and educational privilege that enables some families to provide their offspring with enriched environments, starting at the preschool level.

It is hard to create catch up opportunities in public schools, especially when so many elementary school teachers have week abstract learning/math skills themselves.

And we are a far cry from being a society where most adults understand at least the basic concepts of rate of change or approaching a limit.  People don't understand that Calculus might actually have some relevance.