Actually "begun" is correct in the above sentence..
How can CC push Algebra off to 9th or 10th grade for students with the ability to study it in 8th grade? What coercive powers do they have?
When I was in high school in the 60s, most students studied Algebra in the 9th grade, Geometry in 10th grade, Algebra 3 and Trigonometry in 11th grade and Mathematical Analysis in 12th grade. Some started with Geometry in 9th grade, finishing with Calculus in 12th grade; while others took a took a two-year Algebra program in 9th and 10th grade; or refresher mathematics in 9th grade followed by the two year Algebra program.