I'm going to focus generally on my experiences in middle and high school, since I don't really remember much of what I did in elementary. I dropped out in ninth grade to get my GED, so there's only a junior perspective for high school here. Keep in mind that, though my family isn't rich, I've lived in suburbs and have been to only A-rated schools (apparently lower-rated schools struggle to keep their children from smoking openly).
Social Studies:
I learned this from a textbook, day after day. I remember learning what an archipelago was, and useless factoids about certain random countries. The whole thing was very multicultural-y; we progressed country by country and knew nothing about their actual significance. The most informative thing I remember learned (in sixth grade) was a population density map of China- underpopulated in the west, very populated in the east. There was also a demographic breakdown, which managed to make a simple concept another exercise in rote memorization; we were presented with the list of "ethnic groups" of China, and told that the Han were by far the most populous. No one really cares about a list of random groups in a foreign country, and it's not politically correct to say that Han basically ARE the Chinese surrounded by various subgroups absorbed into modern China.
Another interesting episode is that one of my classmates in ninth grade was surprised to hear that the US had a larger economy than China. I suspect she wasn't the only one. This is one of the great disasters of schooling in the USA. Kids know much more about the world from Fox News, because it actually talks about the world and doesn't list off factoids that We Should Know.
I also recall seeing an overtly pro-war film involving America's withdrawal from Vietnam: natives crying on the streets, screaming that they "can't live with the communists." I think the class was sympathetic, but in an impulsive way; not in a manner that influences political opinion. I don't think they were capable of judging the film in any capacity, simply because they had no context for doing so. Don't break out the tinfoil hats just yet!
Math:
Literally one algorithm after another, every day. If you believe that this is a proper system for teaching young people and doesn't sound like a robot-overlord dystopia, you should have your children taken away from you.
A note: the problems were sometimes analogized to real-life events, called "word problems." I seriously don't understand what people mean when they say this produces critical thinking; it does precisely the opposite. For instance, 9 x 8 = 72 becomes "the baking sale had eight different types of cookie, of each nine were made; how many cookies in all?" When you're doing more advanced stuff this becomes a major problem, because the math is transplanted so directly into the story that it literally trains people not to apply that math in any other way.
I started my math class as one of the best math students in the fifth grade (though I admittedly hated doing the actual subject) and at the end of the sixth I could not even do the work assigned in class. I just fooled around the whole time. That's what it reduced me to.
Oh, and guess what we were doing in the first year of high school? Basic order of operations stuff, the sort of thing I was doing in my first year of middle school!
Grammar:
There is literally no reason for this to ever be taught in any K-12 course beyond "noun, verb, and adjective." If you disagree you should be stripped of your right to vote along with losing custody, and be evaluated for mental competency.
(Children who are actually interested in which part of a sentence is the "predicate," something I don't know to this day, should be provided with a voluntary course. I guarantee it'll be discontinued before the school year is out, though.)
Literature:
This was hit-and-miss for me. I was a reading prodigy from the first grade; not the fastest reader in the class, but the guy who would still be the fastest if bumped up five grades. That's not an exaggeration.
So on one hand I enjoyed being the unrivalled best student and feeling generally like an scientist watching apes sharpen spears. But on the other I did not like assignments that insulted my intelligence, and was almost always bored with what the teachers decided the class should read.
So I can't really judge this objectively. I still think that there's no faster way to suck meaning from literature than to force people to read it, and than be tested on it (presumably to help "appreciate it more").
Science:
I had an excellent teacher in the sixth grade. We did real experiments, and actually learned a bit of useful stuff (one time he had us walk to the school library deliberately not following anyone else's pace, and then measured each person's stride. Interesting lesson into how we accommodate each other unconsciously). The teacher functioned a bit like Cracked.com; he gave us real knowledge couched in the form of bawdy humor. My experience of science in more normal classrooms were still my best, even when I learned directly from textbooks about plate tectonics or weather.
But after getting into high school things were an absolute nightmare. The teacher gave a ridiculous assignment that analogized the scientific method to blind men figuring out what an elephant is from its parts. Seriously. I recall that it took a lot of grunt work to complete, and wasn't conceivably worth anyone's time, so I simply didn't do it. I think this played a role in me dropping out.
Conclusion:
Now this was all typed up at two in the morning, so please excuse me if it comes off as rambling or self-absorbed. I realize some things I've said are rather hyperbolic. I really do think you are an unfit parent if you send your child to this, but I realize that you can't actually take children away from millions of people or arbitrarily revoke voting rights. I'm just saying it's what those people deserve.
As for the teachers, no, they don't deserve that. They deserve to be thrown in prison alongside the "criminal" justice legislators that the US has today. That's what would be happening today if human rights organizations or the UN actually worked as advertised. This is what is going on in millennial schools today: a crime against humanity.
Social Studies:
I learned this from a textbook, day after day. I remember learning what an archipelago was, and useless factoids about certain random countries. The whole thing was very multicultural-y; we progressed country by country and knew nothing about their actual significance. The most informative thing I remember learned (in sixth grade) was a population density map of China- underpopulated in the west, very populated in the east. There was also a demographic breakdown, which managed to make a simple concept another exercise in rote memorization; we were presented with the list of "ethnic groups" of China, and told that the Han were by far the most populous. No one really cares about a list of random groups in a foreign country, and it's not politically correct to say that Han basically ARE the Chinese surrounded by various subgroups absorbed into modern China.
Another interesting episode is that one of my classmates in ninth grade was surprised to hear that the US had a larger economy than China. I suspect she wasn't the only one. This is one of the great disasters of schooling in the USA. Kids know much more about the world from Fox News, because it actually talks about the world and doesn't list off factoids that We Should Know.
I also recall seeing an overtly pro-war film involving America's withdrawal from Vietnam: natives crying on the streets, screaming that they "can't live with the communists." I think the class was sympathetic, but in an impulsive way; not in a manner that influences political opinion. I don't think they were capable of judging the film in any capacity, simply because they had no context for doing so. Don't break out the tinfoil hats just yet!
Math:
Literally one algorithm after another, every day. If you believe that this is a proper system for teaching young people and doesn't sound like a robot-overlord dystopia, you should have your children taken away from you.
A note: the problems were sometimes analogized to real-life events, called "word problems." I seriously don't understand what people mean when they say this produces critical thinking; it does precisely the opposite. For instance, 9 x 8 = 72 becomes "the baking sale had eight different types of cookie, of each nine were made; how many cookies in all?" When you're doing more advanced stuff this becomes a major problem, because the math is transplanted so directly into the story that it literally trains people not to apply that math in any other way.
I started my math class as one of the best math students in the fifth grade (though I admittedly hated doing the actual subject) and at the end of the sixth I could not even do the work assigned in class. I just fooled around the whole time. That's what it reduced me to.
Oh, and guess what we were doing in the first year of high school? Basic order of operations stuff, the sort of thing I was doing in my first year of middle school!
Grammar:
There is literally no reason for this to ever be taught in any K-12 course beyond "noun, verb, and adjective." If you disagree you should be stripped of your right to vote along with losing custody, and be evaluated for mental competency.
(Children who are actually interested in which part of a sentence is the "predicate," something I don't know to this day, should be provided with a voluntary course. I guarantee it'll be discontinued before the school year is out, though.)
Literature:
This was hit-and-miss for me. I was a reading prodigy from the first grade; not the fastest reader in the class, but the guy who would still be the fastest if bumped up five grades. That's not an exaggeration.
So on one hand I enjoyed being the unrivalled best student and feeling generally like an scientist watching apes sharpen spears. But on the other I did not like assignments that insulted my intelligence, and was almost always bored with what the teachers decided the class should read.
So I can't really judge this objectively. I still think that there's no faster way to suck meaning from literature than to force people to read it, and than be tested on it (presumably to help "appreciate it more").
Science:
I had an excellent teacher in the sixth grade. We did real experiments, and actually learned a bit of useful stuff (one time he had us walk to the school library deliberately not following anyone else's pace, and then measured each person's stride. Interesting lesson into how we accommodate each other unconsciously). The teacher functioned a bit like Cracked.com; he gave us real knowledge couched in the form of bawdy humor. My experience of science in more normal classrooms were still my best, even when I learned directly from textbooks about plate tectonics or weather.
But after getting into high school things were an absolute nightmare. The teacher gave a ridiculous assignment that analogized the scientific method to blind men figuring out what an elephant is from its parts. Seriously. I recall that it took a lot of grunt work to complete, and wasn't conceivably worth anyone's time, so I simply didn't do it. I think this played a role in me dropping out.
Conclusion:
Now this was all typed up at two in the morning, so please excuse me if it comes off as rambling or self-absorbed. I realize some things I've said are rather hyperbolic. I really do think you are an unfit parent if you send your child to this, but I realize that you can't actually take children away from millions of people or arbitrarily revoke voting rights. I'm just saying it's what those people deserve.
As for the teachers, no, they don't deserve that. They deserve to be thrown in prison alongside the "criminal" justice legislators that the US has today. That's what would be happening today if human rights organizations or the UN actually worked as advertised. This is what is going on in millennial schools today: a crime against humanity.