Korean grading and school system

I've been grading English books- grammar, sentence writing, speaking, everything.  The first thing I do is grade in fun colors- no students like "red" all over their pages, especially for quotation marks and punctuation.

In the US, a star (example: *) on the number means that problem, answer, sentence is CORRECT and a circle means it's wrong.  I started doing circles and stars.  My students were sad (elementary age) and asking why the answer was wrong and wanted to know the right answer.  I told my students they got the answer right, so they told me, "Teacher, do a circle around the number, not a star."  A star in Korean grading means the answer is wrong and doing stars at the top of the page or on the entire page means the whole page is wrong.  Circles means it's correct.

I have students who will yawn during my class, (which is allowed), but at times, my heart breaks for them because I am one of their many teachers and my English class is one class out of a bunch of academies they have lined up after me.

Students have their school day (elementary ends about 2:30), but it could vary for other schools.  I teach academy classes (학원) in the afternoon and evening.  My class isn't their one and only class.  Students start Korean martial arts classes like Tae Kwon Do, Hapkido, or Japanese Judo.  Students attend other academies like, math, science, social sciences (history, economics, etc), then students go to rooms called 독서실 (Korean study rooms) to continue the studying.  Academy classes happen daily- not one, but a lot.  Korean study rooms are like small desks with wall lined up in a room for students to study.  They are usually silent, so quiet you can hear a pin drop.  Students will go home about 2:30-3:00am and sleep for a couple of hours and start the day again.

I also noticed that Koreans have 3 years of kindergarten, starting at age 5-7, sometimes as young as 4 (remember that Koreans have a different age system, so some as young as 2 start school).  It's not bad, but a coworker of mine said, "there isn't much of a childhood" which made me think because in the US, we have a childhood.  We're sent to daycare, half-day preschool, and told to play with friends.  In Korea, children stay home with a parents (usually mother).  I have not seen a lot of daycares in Korea.  I have seen a lot of mother with children.  I don't know if there's such a thing as a "play date" for children in Korea.  I have to remember, Korean culture is different from what I am used to.

It's been interesting start to learning about the school system.  I am hoping I will learn more.