I suspect there's a huge variation within the US; Chicago area public schools do what you described in Russia, or did anyway.
When relocating years later to California for work, locals seemed to have had access to far fewer opportunities in school.
Besides math, as in the OP's observations, foreign language options seemed to only include Spanish, whereas Chicagoland had French, German, Spanish, Latin, and that included some ancient Greek.
When relocating years later to California for work, locals seemed to have had access to far fewer opportunities in school. Besides math, as in the OP's observations, foreign language options seemed to only include Spanish, whereas Chicagoland had French, German, Spanish, Latin, and that included some ancient Greek.
Just different opportunities, by school district.