Math and Physics are fundamental topics for Engineering or Science majoring students. For Physics, students start to struggle when they meet frictional force for the first time, but about 80 of students are having trouble with any chapters as classroom progress goes advanced. Gravity and Centripetal force is next challenge, then Energy, Momentum, and Harmonic motion. Finally they meet the most difficult chapter of Physics 1 level, Rotational motion. Physics 2 just includes new concepts such as electrical, wave, light, whatever. Physics C covers all of the chapters from 1,2 but solve problems with Calculus concepts. I think Understanding of previous chapters is important in Physics because for example, Kinematics and Dynamics is used for all chapters. However, before taking Physics, finishing all Algebra and Geometry classes is strongly advised. Math is one of the most hated subjects, but if students follow the step correctly, it will become a lot smoother. Studying a topic in advance is probably helpful, so the students fell really confident at school. In Math, understanding of previous chapters is also important. Algebra and Geometry are the foundation of PreCal, and PreCal is the key of next topics, then students understand limit and differentiation. Until AP Calculus AB, all students can catch most chapters as long as they go over a certain amount of problems, but from AP Calculus BC, I think only those who like Math and would choose specific majors are advised to take. One of my students who were in a community college and had almost c- in Physics, tried to study hard with me and successfully finished, and now he successfully transferred to 4 years university now. One of my students whose SAT Math score was 1100 study a lot of concept, and practiced error removing skill, time management. After 3 months, she got 1400+ score (for Math 560 -> 720) I think getting SAT Math more than 700 points is easy but greater 780 needs something else. A students who received greater than 700 but not 750 for SAT Math requires a little different approach. I'm a native Korean and worked in semiconductor industry for a long time. I've taught Korean for a long time as one of my hobbies. I usually help students for basic concepts of Korean and grammars. Also, helped someone who want to travel to Korea. Not only just language is a topic of the session. Some YouTube videos, food, music even traditions are discussed. I've taught people from 6 to 82, but I don't teach younger than 13 any more. Culture and travel tips also the topics. One of my previous students is in Korea and registered Korean University now. When I visited Korea last year, we met and enjoyed some food together. Now I'm her Korean uncle.