By failing your courses and or dropping out. High Schools in the US don't have a static curriculum. Not all students graduating will have taken Algebra 2, Pre-Calc, trig. They also may not have taken Physics or a lot of the other sciences.
Most public High Schools in the US are honestly extremely hard to fail out of. As long as you get C's in all your classes you'll graduate.
I believe at age 16 the government can't force you to go to school anymore. So one would just stop going to class, putting in the "butts in seats" time and never finish the required classes to graduate. I guess that's basically what dropping out means
In the US system you pass/fail each class based on exams and coursework and there is a minimum set of classes required to pass to graduate. The pass/fail is at the class level, there is no separate set of final overall exams as in other systems.
They fail to complete a minimum number of classes with passing grades.
If the bar sounds low and subjective, that’s because it often is, and as such I think it’s mostly useless for colleges looking to measure students against each other to choose who to admit.
My brother passed 12th grade but didn’t have enough English credits to get his diploma. I always thought that was a weird situation to be in, congrats you’re done with school.
The teacher chooses the exact mix per class, so it's possible you fail even if you ace the exams, or pass even if you fail the exams.
This variability is why the standardized tests exist.
I guess it makes sense to do as little as possible to scrape a C or whatever the passing grade is while at high-school and spend all your time optimising for the SAT then instead? Or not that simple?
College admissions are similarly a blend of different criteria: race, high school grades, did one of your parents go to that school (legacy), did your family donate to the school, are you a good athlete, are you a good musician, and of course what is your ACT or SAT score.
The exact weightings are not known to the students applying, but it's safe to say you can't just minmax on the standardized test.
I don't know if you've picked up the tone of some of the other comments in this thread, but people feel very strongly about what factors should be considered in college admissions. Almost no people will defend legacy admissions, few will defend athletic admissions, some will defend musicians, many will defend GPA and standardized testing.
College admissions are zero sum, and different weightings benefit one group over another. For example, "Asians" (the US does not differentiate South Asian [India, etc] from East Asians [China, Korea, Japan]) have very high test scores in the US. If you base your college admissions just on taking the people with the highest test scores, you would get a massive over-representation of Asians. Schools have decided that isn't what they want, so they take people with worse test scores in order to "balance" the student population.
This infuriates the people passed over in the name of "balance", naturally.
