Top student: All my teachers are academic whizzes!

Chapter 1: Someone in the Book

2009 October.

The No. 1 Middle School in Baling County, southern Hunan.

Less than two and a half hours after being reborn at the age of seventeen, Han Chuan confirmed one thing.

"All the books I read in my past life were a complete waste!"

In the classroom during evening self-study, the sound of turning pages could be heard from the front row, while rustling laughter and snoring could be heard from the back row.

Han Chuan looked at the open textbook in front of him. The word "set" in "Mathematics Compulsory Course 1" caught his eye, followed by definitions related to sets.

[The meaning of a set: A set is a collection of certain specified objects, and each object is called an element.]

[...Let set S consist of all elements with a certain property P. Then we can represent the set by describing the common properties of the elements in the set: S = {x | P(x)}.]

For example, the set B consisting of the square roots of 2 can be represented as B = {x | x² = 2}. The set of rational numbers Q and the set of positive real numbers R⁺ can be represented as...

He watched it three times, and then watched it three more times.

Then, expressionless, he closed the book and took a deep breath.

Damn it, I don't understand!

Those symbols and formulas were like encrypted runes; he recognized each one individually, but when put together, they formed the devil's script.

Despite having attended university and scoring 426 on the college entrance exam—not high, but at least passing math—he clearly did well.

But now, he can't even understand what a gathering is!

Is this what it feels like to lose all your cultivation in cultivation novels?

Given his current state, does he still think he can get into Tsinghua or Peking University?

Even getting into Beida Jade Bird is difficult!

In a daze, Han Chuan recalled a scene from before his rebirth.

In 2010, he scored 426 points on the college entrance examination and went to a third-tier university in his province. He spent four years there and was unemployed upon graduation.

Finally, I found a sales job at an educational institution, making phone calls day after day: "**Dear parent, we have a special offer on trial classes for your child..."

Most of the time, the person on the other end of the phone just hangs up. Some listen for a few words and then coldly reply, "I don't need it." Others, upon hearing a marketing call, immediately start swearing...

After doing this for half a year, he suddenly remembered the words he had carved on his desk in his senior year of high school: "Everyone has their own unique talents."

He truly believed it then, so he resolutely resigned and ventured out into the world.

I've worked in sales, delivered food, been a courier, and driven for Didi...

At thirty-five, he was still a failure. His parents urged him to get married and have children, but when he looked at the 100,000 yuan he had painstakingly saved in his bank account, he finally shook his head... He didn't believe it anymore.

Then, he was reborn.

While delivering food late at night, he was sent back eighteen years by a dump truck that ran a red light, and became a seventeen-year-old hero.

As Han Chuan was suspended in the air by the blast, a strange thought popped into his mind.

If he could do it all over again, would the outcome still be the same if he studied hard?

......

Taking a deep breath and recovering from the shock, Han Chuan raised his hand to rub his throbbing temples and whispered words of comfort to himself.

"It's okay, it's okay."

"I just haven't touched these things in a long time. I can always learn them by starting from scratch!"

I'm only in my second year of high school now, I still have a year and a half to take it slow.

If he couldn't understand the high school textbooks, he would start with the middle school textbooks. If he still couldn't understand the middle school textbooks, he would borrow the elementary school textbooks!

Having been given a second chance at life, he may lack other qualities, but he certainly possesses patience and perseverance.

If you're not smart, then you should read more books!

Reading can enlighten people.

Rubbing his temples, Han Chuan pulled out a workbook from a pile of books held together by bookends, trying to do some exercises to get a feel for the work.

Multiple Choice Question 1: Which of the following propositions is true?

A: If 1/x = 1/y, then x = y;

B: If x²=1, then x=1;

C: If x = y, then √x = √y;

D: If x < y, then x² < y²

Han Chuan was dumbfounded when he saw the first question in his math workbook.

No, how come he thinks all four answers are correct?

Should we choose A or B? Or C or D?

He looked at the four options for a full two and a half minutes, and then he was completely dumbfounded.

No, how come he thinks all four answers are correct?

Multiple choice question?

Hey!

Does knowledge really slip away from his brain that quickly?

Han Chuan still remembers that, according to his math teacher, the first multiple-choice question was usually an easy point.

Is he unable to solve even the easy questions now?

I stared at the problems in the workbook for a long time, studied them for ages, and finally squeezed out a pitiful bit of math knowledge from the depths of my brain to eliminate B and D.

And of all that, the only one he could accurately determine was B, because x²=1, so x has two answers, one is 1, and the other is -1.

As for A and C, after thinking for a long time, Han Chuan finally chose the answer he believed to be correct.

C!

He couldn't tell which one, A or C, was correct, but since x was equal to y, the square root of both should be the same.

Thinking about it, Han Chuan turned to the last few pages of the workbook.

He remembered that these workbooks seemed to have answers at the end.

Sure enough, the last few pages contained the answers to the entire workbook, but the answer to the first question surprised him.

Correct answer: A.

???

No, even if you have to choose one of two, the one you feel most strongly about and think is right is wrong?

Han Chuan remained silent for three seconds.

Well, that's how math is. Right is right, and wrong is wrong. It never takes personal feelings as the standard.

But where exactly did he go wrong in his choice?

Suddenly, Han Chuan remembered Lao Liu, the math teacher he had a good relationship with at his first job at the educational institution before his rebirth.

Once, he and Lao Liu had a late-night snack and drank too much. Half-drunk, he said that if he could live his life again, he would definitely study hard, get into a good university, and then do research!

At the very least, you should study a good major and find a job with an annual salary of 500,000 to 600,000 yuan.

Upon hearing this, Old Liu laughed heartily and patted him on the shoulder.

"Xiao Han, sometimes you have to accept your fate!"

"With a score of just over 400 on the college entrance exam, what makes you think you'll get into a good university or become a good teacher?"

"Seriously, most people in this world are just not cut out for studying, no matter how hard you push yourself."

"I've been teaching for twenty years and I've seen far too many students like you—either you don't try, or you just can't grasp the concept!"

At that time, he had just entered the workforce and was full of resentment, taking Lao Liu's words as a cold shower.

After all, every teacher who had taught him since childhood had said, "This child has talent, but he just doesn't study hard."

At that time, he believed it to be true and thought that what the teacher said was right. He thought he could get into a good university, a 985 or 211 university, or even Tsinghua or Peking University.

But now, looking at the problems in his math workbook, he suddenly felt that what Lao Liu had said might have been true.

He's probably just one of the majority of people, not as talented as his teacher said in his past life; he might really not be cut out for it.

But Han Chuan didn't want to give up; what he had in abundance was tenacity!

He took a deep breath, closed the workbook, reopened the math textbook, and found the section on true and false propositions.

A foolish person uses a foolish method.

If you don't understand it the first time, read it ten times. If you still don't understand it after ten times, read it a hundred times!

He read it down word by word.

【1.1 What is a proposition?】

Definition: Statements that can be judged as true or false (e.g., 2+3=5; the sun rises in the west).

Propositional elements: Subject (object of the statement): e.g., "2+3"; Predicate (content of the judgment): e.g., "equals 5"; Judgment word (whether it is true or false)...

Han Chuan began to read word by word. Having almost forgotten everything, he could only use the most rudimentary method to try and regain the knowledge that once belonged to him.

The key to determining the truth value of a proposition lies in the logical relationship between the conditions and the conclusion. A proposition being true means that "if the conditions are true, then the conclusion must also be true."

He read very slowly.

It's not that I don't want to be fast, it's that I can't be fast.

After reading each sentence, he would stop and think about what it was actually saying.

Logical necessity, consistency, and perpetual validity...

He recognized each of these words individually, but when put together they formed a wall.

Having almost forgotten everything, he can only resort to the most rudimentary method to retrieve the knowledge that once belonged to him.

After reading it the first time, Han Chuan felt that nothing was retained in his mind, except that "the proposition is true" requires two conditions to be met.

First, it holds true under all conditions; second, it cannot contradict known axioms.

So he read it a second time.

The second attempt was slightly better than the first. He tried to apply these two conditions to the multiple-choice question from before—Option A, "If 1/x = 1/y, then x = y," is this true under all conditions?

He thought about it and felt that it seemed to make sense.

But why is option C, "If x=y, then √x=√y", not a true proposition?

No, option C is also a true statement, right? If x = y, then their square roots should also be equal.

Han Chuan frowned, then flipped to the answer page and glanced at it again—the correct answer was A.

He couldn't figure it out.

So he read it a third time from the beginning, and then began to look for the reason why answer C was wrong.

This time he read even slower, not on purpose, but because he was trying to let each word linger in his mind a little longer, to think about it a little longer, and to savor it a little longer.

Just like when we were kids, we would eat a piece of candy and be reluctant to swallow it, so we would keep it in our mouths for a while longer.

......

The third time, the fourth time... The classroom was quiet. Evening self-study was not over yet. Some of the students around me were sleeping on their desks. Occasionally, the rustling of turning pages and the whistles of athletes training on the playground could be heard.

But these sounds seemed to be separated by a transparent film.

Han Chuan's attention became more and more focused, and his vision gradually narrowed, leaving only that small world on the textbook.

He was simply instinctively, almost greedily, trying to cram those words into his mind.

Then, something strange happened.

The words in his field of vision began to move.

It wasn't a hallucination, nor was it an illusion—Han Chuan was certain he was fully conscious, but the words in the textbook were indeed moving.

They floated up from the paper, as if liberated from the two-dimensional plane by some force, and turned into three-dimensional symbols with a faint halo.

"You, a high school student, don't understand something as simple as setting a topic that even elementary school students understand?"

The knowledge from the book was rearranged into a sentence, carrying a sense of condescending scrutiny.

Han Chuan was stunned for a moment, then subconsciously rubbed his eyes, thinking he was hallucinating.

"I'm asking you a question."

Immediately afterwards, the symbol changed again.

"What's going on?"

Han Chuan was completely bewildered and turned to look around.

The classroom was quiet. His deskmate was still asleep, and the people in the back row were still chatting. No one noticed him.

Coming to his senses, he looked back at the textbook on the table. The words on it still floated before his eyes, sending chills down his spine.

Looking at the surreal scene before him, Han Chuan opened his mouth, unsure whether to answer or how to answer.

Soon, new handwriting appeared on the textbook. This time it was written quickly, with strokes showing obvious impatience.

"Can you hear me?"

Upon seeing the question, Han Chuan subconsciously nodded before realizing that he seemed to have seen something, not heard it.

But whether we hear or see it is not important; the key is what this thing in front of us actually is.

And who is speaking?

Could it be that this textbook has come to life on its own?

Didn't we agree that animals wouldn't be allowed to become spirits after the founding of the People's Republic of China?

"As long as I can hear it, that's fine."

New writing appeared on the book. After a pause of one second, the new writing slowly emerged, larger than before, as if the writer had deliberately increased the pressure.

"With such a terrible foundation, how did you even get into high school?"

Han Chuan: "..."

Before he could react, the line of text was crossed out again.

It was truly crossed out; a sharp horizontal line cut through the middle of the word, and then a new sentence was written next to it:

"Fine, since we're already here and have nothing else to do, I'll teach you."

"Keep a close eye on these eyes, start with the wrong answers!"

This sounded exactly like a math teacher's tone, causing Han Chuan to nod subconsciously.

"Why is C: If x=y, then √x=√y is not a true proposition? Do you even have the concept of negative numbers in your mind?"

"Can you take the square root of a negative number?! Use your brain to think about it!!"

False teachings fill countless books, but true teachings can be conveyed in a single sentence.

When Han Chuan saw this sentence, it immediately became clear why option C was wrong.

"yes!"

"Negative numbers don't have real square roots!"

Han Chuan muttered something to himself, then suddenly understood.

This seems to be knowledge from junior high school.

In other words, his current knowledge, at least in mathematics, is not even as good as that of a junior high school student.

Thinking of this, Han Chuan twitched the corners of his mouth, feeling somewhat amused and exasperated.

Has his academic level regressed from undergraduate to junior high school level?

While searching through his math textbook, he finally found a relevant description in his first-year high school textbook.

Every positive real number has two square roots that are opposites of each other (for example, the square roots of 4 are ±2).

The square root of zero is zero itself.

Negative numbers have no square root in the real number range because there is no real number x such that x² equals a negative number.

That's all. Looking at the description above, he truly understood this time!

"By the way, who are you?"

"Have the books come to life?"

Coming to his senses, Han Chuan suddenly remembered something, and looked back at the textbook, staring curiously at the word "floating" still on it, and asked.

"You're reading the textbook I wrote, don't you know who I am?"

.....