In the 80s it was not uncommon (at least in the Jesuit schools I attended) that Algebraic concepts would be introduced to students at early as 5th grade, but definitely by junior high (7th/8th) and while I hated math (especially at the time) it wasn't something I thought I needed to be older to grok...I needed less psychotic, rigid teaching from nuns with all the compassion of Stalin, and more guidance, which other students in similar schools got in spades and had no issue with.
In the 80s it was not uncommon (at least in the Jesuit schools I attended) that Algebraic concepts would be introduced to students at early as 5th grade, but definitely by junior high (7th/8th) and while I hated math (especially at the time) it wasn't something I thought I needed to be older to grok...I needed less psychotic, rigid teaching from nuns with all the compassion of Stalin, and more guidance, which other students in similar schools got in spades and had no issue with.