SEE HERE I suppose if you don't care about education you might think this is a non-story. But what it comes down to is that immorality encouraged by the state is non-negotiable even in a math class.
I regret ever sending any of my children to a public school and I've been watching my grandchildren be indoctrinated so that they are rude to their parents and grandparents when hot-button issues come up that have been propagandized in the classrooms. They don't have any arguments you understand. They don't apply critical thinking skills. What they do is claim that their parents are bigots because that is what the school told them.
We have several generations of this now and it has so dumbed down the public square that few know how the nation was founded and what the founding principles and documents say. Instead they have been indoctrinated in liberal and progressive beliefs without any foundation in reason and they act like good little automatons, doing what they are told and very little more. They are drained of creativity and turned into robots.
C.S. Lewis wrote a whole book about it called "The Abolition of Man." It was prescient when he wrote it and it is being acted out before our very eyes today.