I was an instructor for MTH142 Calculus II in the second summer session 2020 at the University of Rochester. Overall rating was 4.71 out of 5.

Here are some feedbacks from evaluations from the report:

I am seriously interested in Calculus way more after this course, and I was hoping there might be a way for me to get more involved via tutoring.

I believe Professor Yoo's strengths include being very helpful and understanding, which makes her very approachable. She is not condescending and makes it clear she wants everyone to do well. She is also great at explaining the course material and giving context as to what we are actually doing and why, in order to help us understand the topics. I loved having her as a professor and would love to have her again.

Professor Yoo is sincere, organized, and loves what she teaches and does with a passion that she wishes to pass on to her students. She is always eager to communicate with students and willing to help.

I think the course was handled very well because of Professor Yoo's ability to be a strong teacher even with the obstacle of not having in person class.

Professor Yoo is extremely sincere and has the utmost respect for her students, always letting us know that she is available for questions (and emails back in a timely manner). She truly wants us to make the subject matter enjoyable for us in the same way she enjoys it.

About teaching skills:

Lectures were concise and very straightforward. Professor Yoo would always begin with motivations for the topic that day and why learning the concept would be helpful. Everything was very well organized and easy to understand.

Professor Yoo was very good at explaining what it was we were going to be covering every lecture, and explained to us how to do it, and then proceeded with various examples to help us understand. She consistently would ask if it made sense and make sure everyone understood what she was doing before moving on.

The instructor did an excellent job in the structuring of her lectures and worked to include a significant amount of examples during the lectures.

Professor Yoo always asked us if we had any questions after explaining new/challenging concepts and would explain anything more clearly accordingly. She would always go through several examples for each lecture to have us understand the concepts more thoroughly, and emphasize the importance of practicing problems for each topic.

Some interesting problems

I was a TA for STEM for all Summer Program 2019. The instructor was Vitaly Lorman and the topic was Knot theory. There is an interesting problem (Exercise 4.4), which is in the knot book written by Adams:

2. Another interesting problem is to figure out "?". I learned this problem during my visit in Hong Kong.

3. Can you turn a sphere inside out in a 3-dimensional space without cutting or tearing? I had a fun conversation with Charlotte Aten during the Thanksgiving 2020! sphere inversion, stackexchange.

4. Can you guess what's next?

1, 11, 21, 1211, 111221, 312211, 13112221, ?

This sequence was introduced and analyzed by John Conway, and there is the answer.

5. An interesting problem about infinity! Video : "How An Infinite Hotel Ran Out Of Room" (It is called, "Hilbert's Hotel.")

6. Have you heard that 13 is a lucky number? : What is a lucky number?.

7. Can you explain this staircase paradox? The picture is from Wikipedia.

8. Can you guess the number in (?)? The answer is not 15. I learned about this problem during my visit to Brussels.