My best teacher I ever had was Mrs. Kim San. She has taught in Sontor Mok Secondary School for many years. I used to study with her at seventh grade. She was tall, slim, and she had long black hair. She usually used to wear shirt and trousers. Sometime, she was wearing a beautiful dress at a special day, especially, the school’s party. She taught us math and she was enthusiastic about her subject. Her lesson was interesting and she explained everything clearly such as formulas and theories of math. She always allowed us to practice with her subject at all time. That was a method to understanding about it. She used to help the students when they had a problem or didn’t understand her lesson. Especially, she gave the cleat answer to our question. All students particularly liked her so much because she was open-minded, friendly, and polite. For example, she helped the poor students to study an extra time class without paid their money. If we hadn’t enough money, we would ask her to study. While she was teaching, she always smiled at the students. She had some kind words to say to the student in her class. In the class, she punished the students who behave badly, but she also encouraged the students who tried to study hard. She was different from my history teacher, who was lost her temper. She always shouted at us every time. All the students didn’t like her so much, and her class was boring. She was not the same to my mathematics teacher. I would like to meet her again because she gave a lot of knowledge to me. I will say thank you to her if I meet her again.