Liu Chen couldn't help but clap his hands and exclaimed: "It seems that some students have discovered this rule. It's very good. Interested students can verify it by themselves. There is also such a rule for three-digit numbers. [Novel is updated quickly, no pop-ups, please search]"

He paused deliberately for five seconds, and sure enough, He Qian shouted: "495."

"Correct." Liu Chen said expressionlessly. Seeing the boy's excited and proud look on his face, he knew that he had become interested and had fallen into the situation of guiding him, and did not praise him at all.

The other students were still confused and didn't know what was going on.

"Students might as well experiment with these interesting phenomena after class. In fact, starting from this question, we can also ask a question, that is, in addition to three-digit numbers, four-digit numbers have this rule, so are there five-digit numbers, six-digit numbers, and seven-digit numbers? I can tell you that this phenomenon is called a digital black hole, also called a kaprekar constant."

As soon as the first small question was finished, He Qian was attracted by Liu Chen's lecture. This knowledge was not something that those teachers could tell.

Liu Chen ignored the students' reactions and continued to talk.

"Start with any positive integer, repeat the following operation: If this number is an even number, divide it by 2; if this number is an odd number, expand it to 3 times and then add 1. What will happen?"

Like a human brain computer, He Qian quickly shouted: "In the end, it will always become a cycle of 4, 2, 1, 4, 2, 1, 1, …."

Obviously, such slander makes him very fun. I can know whatever you say immediately, and see what you have to say.

Xue Song said worriedly: "Liu Chen said this and it's not difficult for He Qian. This is simply giving him a chance to show off."

Ling'er knew Liu Chen's personality well and frowned and thoughtful.

Yuan Zheng smiled and said, "Haha, I think it's very interesting. Listen patiently. Even if you perform on the spot, this junior Liu Chen should have more than just this skill. After all, if Zhuo Ling takes the initiative to invite him, he will never be a mediocre person."

Holding hands on your chest and watching.

On the surface, Liu Chen is indeed being teased by He Qian.

"Does the sequence eventually become a 4, 2, 1 loop for all numbers?"

He Qian frowned again and shouted for a moment: "This is not simple!"

It seems that Liu Chen is going to be despised again.

But he continued to say indifferently: "This problem can be said to be a huge pit. At first glance, the problem is very simple and there are many breakthroughs. So many mathematicians jumped into it. However, they didn't know that it was easy to go in and out, and many mathematicians didn't get this problem until they died. There were countless mathematicians who had been involved in it, and they extended the ollatz conjecture, syrau color problem, ka pants Tani problem, has color algorithm, ulam problem, etc. The simple classmate who just said that if he could solve this problem in his lifetime, it would be enough to leave a name for academic history."

Ordinary children don’t know that such a simple problem is indeed the most complex problem.

"Breaking nonsense, numbers within a thousand are in line with this rule!"

He Qian's voice was very disdainful. With his knowledge, he would not think that such pediatric problems were difficult.

Liu Chen smiled, "So what if the numerical symbols under 10,000 are in line with them?"

He Qian gritted his teeth and tried his best to calculate, and it took only a few minutes to shout: "I'm all satisfied."

This child is indeed very powerful. He definitely does not count every number by calculating it. It is classification verification. For children in the second grade of junior high school, it is very difficult to master the methodology by themselves. It is like a Gaussian.

"So what if the number signs within 100 million are in line?"

The other students seemed to understand but relished it and thought it was amazing.

He Qian didn't want to admit defeat, so he gritted his teeth and tried all kinds of ways.

Liu Chen poured cold water directly, "In number theory, as long as it is extended to infinite numbers, it is very difficult to prove, because you can't prove it one by one by one, the famous Riemann conjecture, Fermat's theorem, and the Goldbach's conjecture all belong to this situation, and the same is true for the 3+1 problem. Until now, mathematicians still have no proof. This rule holds true for all numbers. If anyone can prove this problem, then he will be one of the greatest mathematicians, at least one of the most famous top ten people on this earth, at least much better than the well-known Chen Jingrun and Hua Luogeng."

The students suddenly became a pot of porridge. What sounds simple actually solved the problem that can surpass the famous mathematicians in the textbook. For these children, it was a world of openness, and a stream of passion was pouring out. Students who usually claimed to be smart couldn't wait to take out paper and pen to verify it. They fantasize that they could solve the problem in one go, making a name for themselves... and so on, young people are always impulsive and naive, full of fantasy.

Liu Chen's speech is extremely simple for these students. Those who are in a bad math and fail the exam can easily understand these problems, but they are extremely different, and the impact on them can be imagined.

"What do you say is what you want? Humph, who do you think you are?" He Qian obviously couldn't accept the stumped failure, but he couldn't do anything about such a huge number.

Liu Chen ignored him and continued, "It is the same for a number to read forward and reverse, so we call it palindrome. Choose any number and add the number you get after writing it in reverse until a palindrome number is obtained. What is the palindrome number of 67?"

"It's calculated in two steps, 484, the level of kindergarten."

“Where is 69?”

"4884, this is the level of elementary school students. We are junior high school students."

Faced with such a monster student, I'm afraid any teacher will collapse. Fortunately, Liu Chen is not an ordinary teacher. Not only is he a high level of mathematics, but he is also a strong mentality. He has seen many examples of this interesting mathematics. It is no problem to abuse this boy. Cold Ran said: "Where is 89?"

After a while, He Qian didn't say anything.

He Qian couldn't help but sweat a little on his forehead. The sudden increase in difficulty once again made him collapse. It would be fine if he couldn't calculate the endless numbers one by one. Why was there nothing he could do about such a simple calculation just now? In a series of confrontations, the students spontaneously looked at him, feeling a pressure like a ray of light on his back, and their whole body was hot.

Yuan Zheng could see clearly from the side and laughed in a low voice: "Liu Chen is so smart. From shallow to deep, giving He Qian confidence and then hitting his arrogance, maybe it will be really useful."

"There is no palindrome number at all!" He Qian, who had calculated eighteen steps but still had no results, was on the verge of collapse. It was almost a super large number.

"Isn't there really?" Liu Chen smiled. (To be continued.)
Chapter completed!