12th

Also, I'm Math/CS teacher and currently teach 8th through 12th graders.

There is extracurricular activities of course but it is not the same as starting with 1st grade and potentially being with the same group of people until the 12th grade.

He wrote a treatise in the Arabic language during the 9th century, which was translated into Latin in the 12th century under the title Algoritmi de numero Indorum.

Those three books talk about the 1500-1700 Nayaka rule, languages in 1700-1800 and the third book's summary says it talks about the 12th-14th centuries.

THe latter would be more intellectually honest to say "really, we would be lucky if we were in the same place as the alchemists were in the 12th century".

In the mid-eighties I was a process engineer for a printed-circuit-board company whose production staff was predominantly female and with an education level of 10th to 12th grade.

And they do live in the 12th century in some respects, they're just doing it within the comfort of their 21st century homes, with their 21st century cars, weapons, and infrastructure.