All-round mathematician

Chapter 66

On Monday, Class [-] of the third grade was informed by the math teacher that Yang Fan from Class [-] and Class [-] would explain the mid-term exam papers in the evening self-study.

Make a splash in school.

This is an unprecedented move in the 20 years since the establishment of the Affiliated Middle School.If it is said that they help each other in normal times, the communication is fine.

What is it this time?It is a public class.

Don't say that your own school doesn't have it, even if you put it in the whole Wuzhou, there won't be one.What does it mean to let students act as teachers?

The name Yang Fan has been constantly bombarded in the school in the past month, all kinds of behaviors are unimaginable, and the name of contemporary mathematics is well deserved.

Is it too much when it comes to lecturing?

At [-]:[-], the amphitheater was already full of people, and all the members of the third and sixth classes were present.

In the first and second grades of high school, the mathematics teacher has asked each class to send two to five class leaders to observe, not to listen to the paper questions, but to listen to mathematical thinking.

Chen Changyi arranged for each class to sit down, and the first row was high class one by one, and they were resettled.There are two rows per shift, up to row No.12.There are also remaining seats on both sides, and the front is handed over to the high school students who are observing.Only in this way, teachers have no opinion.

"Everyone remember to bring your mobile phone or recorder." Chen Changyi shouted.

"Teacher Chen, bring them all."

"We are prepared."

Chen Changyi nodded, and looked to the rear left, where all the high school math teachers were present, as well as their electronic equipment. On the right rear, there were scattered people of all levels with doubts, teachers of junior high school students, and teachers of other high school subjects.

Even the principal, Qu Mengxiu, was among those people. The school attached great importance to the open class this time.

Looking at the time, it was almost time, and the long-awaited protagonist had already arrived at the door.Chen Changyi left the podium to him, and ran back to the high school mathematics group by himself.

Yang Fan came to the podium, spread out the paper, and supported the edge of the table with both hands, with a calm and serious expression.

"It's nothing to be nervous about." Yang Fan secretly said, "It's not the first time, you can shout in front of 2000 people, 300 people, that's it."

Put on the headset and look down calmly.

Under the stage, Qu Mengxiu sat in a pile of brains with several school leaders.

"Just relying on this mentality and tolerance, we have distanced ourselves from ordinary students." Qu Mengxiu said with emotion.

"Yes, principal, this student is not like a child at all. I remember the first time I taught a class, my legs were weak, and I almost couldn't get off the stage."

The third and sixth classes of high school are all concentrated in front of the podium.The student looked up, and there was only one figure in his eyes.

The first Qiming has all sorts of complexities on his face, his grades have dominated his peers for three years, and no one has asked him to teach others, etc.

"I hope you can go farther, and the source of the river..." Cui Qiming whispered.Yang Fan and Jiang Shuiyuan are two mountains that weigh on his heart, and the same scene seems to appear again.

That Jiang Shuiyuan worked hard in the second semester of the third year of junior high school, and brought down Cui Qiming, who had dominated for three years, to the dominant position. In the senior high school entrance examination, Cui Qiming ranked third in the city, and he was unwilling to go to the ninth middle school, because he didn't want to see Jiang Shuiyuan's hypocritical face. .

However, three years later, the city's unified examination, Jiang Shuiyuan ranked first in the city every year, and Cui Qiming hovered between third and fifth.

A bell rang, awakening the nympho Xiao Hongye.She wiped her saliva to speed up the progress.

"Hi, hello." The headset worked well, and Yang Fan smiled and said, "Hello, everyone. I am Yang Fan from Class [-], Grade [-]. Today I will explain the midterm paper to you. If you have any questions, you can raise your hand boldly."

The classroom was silent, and no one spoke.

"The first question is a multiple-choice question. The answer is A. Please raise your hand if you are wrong."

Dozens of third graders raised their hands.

There were 254 students in Class 253 and 14 of Senior High School, but there were actually 5 students.[-] people raised their hands, accounting for about [-]%, this question is passed.

"Because of time constraints, this question is asked by the students themselves. Next question, choose B. Wrong students raise their hands."

18 people raised their hands, accounting for 7%, this question is passed.

"The third question, the answer is B, raise your hand."

……

The mediocre beginning made several math teachers suspicious.

"That's it, isn't it..."

"The reason we are looking for is not necessarily correct."

"What do you think, Teacher Chen?"

Just as Chen Changyi was about to speak, he snorted coldly in his ear: "You can go if you're impatient, don't make noise."

With such a proud voice, there is no one else among the math teachers except Feng Yao.

"Wait a little longer," said the good old Chen Changyi.

Li Jianxing, the representative of the first year of high school, is the third in the midterm exam.Hearing the discussion of the math teacher behind him, he laughed. Teacher Feng would do anything for that student, and even jumped out to die.

That senior is dedicated to shocking people badly, the more bland the beginning, the more amazing the later stage.Li Jianxing looked enviously at the stage, whether he had the opportunity to come to an open class, then his high school life would not be in vain.

The start was like water, until the eighth question.

"Choose D, raise your hand."

83 people raised their hands, more than 30%, it was controversial.

"Okay, now, let's take a look at this question, why so many people make mistakes."

The drowsy audience was jolted, here they come.

"In this question, B and D are very similar. It is because I chose B that I raised my hand wrongly."

82 people and 68 raised their hands.

"That's it. Most of the students made mistakes because they were disturbed by B. Let's look at the content of the topic. The method here may be different from that of the teacher. First, we think that B is accurate, and then deduce the topic from the back, and directly use B as the Bring in the answer, whether it is feasible."

In △ABC, the opposite sides of interior angles A, B, and C are a, b, and c respectively. If asin Bcos C+csin Bcos A=half of b, and a>b, then ∠B=().

A: π of thirds B [-]/[-]s π C [-]/[-]s π D π of sixths
According to the law of sines: asin Bcos C＋csin Bcos A＝half b
……

"At this point, it is clear at a glance that it is wrong to bring B into the question. If B is to be the correct answer, how should we change the question? Who knows, please raise your hand."

Brush, more than 1 hands held high at the same time.

"Beautiful, really beautiful." A teacher in the mathematics group said excitedly, "This is to use one question as two questions, and consolidate the knowledge points twice."

"It's not just that, the reverse deduction of the questions is to completely dissect similar questions. It can be said that these students will not make the same question twice."

"There is a saying that is good, never leave it. One knowledge point is actually the third one. This method is very good."

The buzzing discussion of the math teacher does not affect the whole classroom at all.

Yang Fan looked at the classmate who raised his hand, and pointed: "Well, that..."

Immediately froze, that classmate couldn't name himself, how to name him.From my own perspective, I can determine a certain one, but from the perspective of students, all of them seem to point to them.

With one finger, spread to the audience, and a few can point out five people.

Thinking of this, Yang Fan said: "Students, I ask you to change seats, it's okay."

(End of this chapter)