The new, controversial common core curriculum has led nine Hillsboro, Oregon parents to pull their children from government run schools. Instead, the parents are opting to homeschool for a part of the day.

KATU-TV reports that one time “A” math students have seen their grades tumble to a “D.”

Because of that, the mothers of those students have pulled their children from math classes and are instead working together to teach those lessons at home.