Please find below an alternative version to your piece of writing:
—-
When I think back on teachers who had an impact on me, one teacher who taught me math in middle school comes to mind. He was a teacher who recognized and tried to advise me on my weakness. When I was in school, I was very shy, so giving a presentation was the last thing on my mind. I was supposed to give a presentation in class one day, but I couldn't because I was too nervous, and this teacher recognized that it was a serious problem so, he encouraged me.
He kept doing so, and I gradually began to gain a little more confidence. It made a significant difference for me.
He was also well-known in school for his unique teaching style. He taught us how to do math. Unfortunately, I don't remember his name, but I referred to him as 'DDongDangu teacher.' I called him 'DDongDangu teacher' because he used to say 'DDongDangu' in class when explaining a concept. I mean, when he needed to explain a difficult concept to us, he did so in his own unique style in such a way that it immediately went into long term memory. He used a variety of hand gestures.
I lost contact with him after middle school, but he remains in my memory.
——
Hi Mari, how are you doing? You did a good job. Well done. Practice makes perfect!