As soon as Liu Meng's question came out, everyone took out paper and pen to calculate it. Although Liu Meng just said that thinking is the most important, when time is tight, the students are still used to starting to calculate. This is the influence of the mindset. In fact, this question is like a question with 1+2+3 all the way to 100. It is easy to find the right entry point.

Time flies quickly, and a minute passed immediately. Liu Meng asked with a smile, "I wonder if any of the students have got the answer?" The students at the scene realized that they had not yet figured out the situation. Where could there be any result? Liu Meng didn't expect anyone to succeed. Suddenly, a small hand was raised. It was the thin and small classmate before. Liu Meng was surprised and said, "Does this classmate know the answer?"

The thin and tiny student stood up and said, "This is of course a question of summing the series. But it has another clever answer: Since the two cars are 200 kilometers apart and travel kilometers per hour, it takes 2 hours to collide. Therefore, the fly flies for 2 hours, so it must have flew 150 kilometers. As Professor Liu said, changing the idea, it will be very simple to calculate the flight time without calculating the flight distance step by step."

Liu Meng was particularly surprised. He didn't expect that a classmate from Sishui No. 1 Middle School responded so quickly. He couldn't help but ask: "It's totally correct, what's your name?"

The classmate said shyly: "My name is Ji Bin, from Class 3, Grade 2."

"Well, sit down, it's great. If you keep interested in mathematics, you will definitely be an amazing mathematician in the future." Liu Meng gave him a high evaluation. He continued: "It is said that at a dinner party, a young man met Feng Neumann and asked him this question. Feng Neumann pondered for a few seconds and replied: Oh. Of course it is 150 kilometers. The young man was shocked a little and thought to himself that Teacher Feng was really awesome, so he flattered. 'Ah, Teacher Feng was indeed a clever, and he immediately thought of the method of multiplying time by the speed of flies.' Feng Neumann replied: What? I asked the sum of the series."

After Liu Meng told a little joke, the students in the audience burst into laughter.

The speech ended, and the students surrounded Liu Meng and refused to go back to the classroom. There were all questions. Many female students looked at Liu Meng with admiration and looked at him with their eyes shining. They felt that this elder brother, who was only a few years older, was too powerful. His extensive knowledge, confidence and maturity in his experience attracted the girls at this stage. I don’t know who started it, so everyone took out their notebooks and asked Professor Liu to sign it. Liu Meng was unwilling to refuse. He wrote some words of encouragement in everyone’s notebook. After this trouble, Liu Meng was able to escape after half an hour of the speech and returned to the Mammoth Science and Technology Building next to Sishui No. 1 Middle School.

That night, Liu Meng was thinking alone about the place where the Goldbach conjecture was stuck. The guard came to inform him that a classmate asked to see him, saying that he was named Ji Bin. Liu Meng was very impressed by the student. So he let him in and Ji Bin came to Liu Meng's study. He saw a lot of books on various maths, which were arranged by Teacher Kong's house at the time, so it was easy to check.

"Sit." Liu Meng smiled very kindly. After Ji Bin sat down, he looked around curiously. He hadn't seen so many math books at once. "Student Ji, is there anything you need to ask me for?"

Ji Bin was a little nervous and took out a few sheets of A4 paper, but these papers were not the kind of regular printing paper. Instead, there was a small shop in the north of Sishui No. 1 Middle School that specialized in buying large-faced paper. The students all went to weigh them according to the pounds. After they bought them, they cut them into the size of A4 paper. "Teacher Liu, I... I really want to solve the Goldbach conjecture. If you have any ideas, come to you. I... I'm here."

Seeing that he was not joking, Liu Meng was shocked at the moment, no? A second-year high school student solved the problem of being stuck in the world for more than a hundred years in one afternoon. He couldn't wait to look over now, Ji Bin felt a little embarrassed, "I just calculated according to my own understanding, and I don't know if it's right." Liu Meng thought that it would be fine if it was right? Although he was vibrating in his heart, he hoped that he could really solve it and fulfilled his promise to Teacher Kong.

"Proof of elementary mathematics?" Liu Meng couldn't help but speak out after just looking at him. He had never thought about this in the past. The reason was that it was impossible to use elementary mathematics methods to prove this conjecture. He had to use higher mathematical tools. But after reading it briefly, although this method was primitive, there was no problem for a while.

I saw that the two initial forms of the Goldbach conjecture were written on the paper: (1) Any even number not less than 6 can be represented as the sum of two odd prime numbers, such as 6=3+3, 8=5+3, 10=7+3, 12=7+5, etc. (2) Any odd number not less than 9 can be represented as the sum of three odd prime numbers. For example, 9=3+3+3, 11=3+3+5, 13=3+5+5, etc.

The writing is very simple, and even Liu Meng doesn't doubt it. Is it really that simple?

Seeing Liu Meng's brow frowned very high, Ji Bin said nervously: "When I was having lunch, I suddenly thought that using even sieving method could prove the 1+1 problem of Goldbach's conjecture in the field of elementary mathematics."

Liu Meng was about to go crazy. He didn't see any mistakes when he watched it for the first time. His thinking was very clear and complete. Although it looked really simple, he couldn't help but read it carefully.

"Suppose n is any even number not less than 6: 6, 8, 10‥‥‥n, xn is any positive integer no greater than n/2: 1, 2, 3...n/2, then n can be represented as the sum of n/2 to positive integers: 1+(n-1), 2+(n-2), 3+(n-3)…n/2+n/2, expressed as: n=xn+(n-xn); in this n/2 logarithm, each logarithm contains two addends. If one addend in each logarithm is a composite number or 1, the pair of number in which it is located must be removed, then the rest are pairs of numbers that only contain prime numbers. We assume that the number of such prime pairs is n, then as long as it is proved that n≥1 when n≥no, the Goldbach conjecture (1) is true..."

Liu Meng couldn't help but tap his fingers on the table, and his face gradually became solemn. After reading it again, he was a little disappointed after thinking about it. He sighed and said, "When I read it for the first time, I really thought that I had simply solved the conjecture by using this method. After reading it again, I found that you just gave a few examples of satisfying the conditions in the article. This method can indeed solve most numbers, but the simplest numbers such as 9 and 144 do not meet your proof conditions. What is the most difficult thing about the Goldbach conjecture? Do you know?"

Ji Bin looked disappointed. As a young man, he was always full of passion and fantasy, and shook his head.

"The most difficult thing is that this is a proof that all infinite integers are valid. This method is untenable. Even if no incomplete numbers are found within tens of billions, how can we ensure that there is no incomplete situation in the subsequent infinite numbers? Once discovered, the entire proof method will be overturned."

Ji Bin nodded sadly.

Seeing his sad look, Liu Meng realized that he was a little stern, and then smiled and said, "Although you have not been able to really solve the conjecture, it has proved your mathematical talent. You can come to my study in the future. Even when I am not in Sishui, you can ask me any questions." This is because he has trained Ji Bin as a student. Influenced by Teacher Kong, Liu Meng's mind has become much broader and the height he stands is also different.

Ji Bin nodded after thinking about it.

After Ji Bin left, Liu Meng thought about the steps he wrote with paper. Although these steps were wrong, Liu Meng also broke through the previous thinking constellation. Is it possible for the Goldbach conjecture to solve it through elementary mathematics? Or can one of the steps be transformed through elementary mathematics? You should know that the essence of mathematics is actually in elementary mathematics. Advanced mathematics is just a means, because the philosophy contained in elementary mathematics is the most test of thinking ability. For example, how to use ruled rules to make regular heptagrams requires genius thinking, which is also Euler's most proud work.

Liu Meng still remembers that when he was in elementary school, there was an old peddler in the same village who often liked to give some questions to children. At that time, there was a question that said an old lady was carrying a basket of eggs to the market to sell, but was accidentally knocked down by a hawker riding a horse. The eggs were broken all over the floor, so the vendor had to compensate the old lady. The old lady was afraid that she would count the eggs wrong, so she counted the eggs one by one, and the last one left, and the last one left, three by three by three by pile, and the last one left, four by four by pile, five by pile, and five by pile, and six by pile, and one left, so how many eggs are there in this basket?

At that time, in addition to Liu Meng sitting next to him, there was also a junior high school student who was there. When the junior high school student heard this question, he immediately thought about writing multiple equations to solve it. The high school student thought about using quadratic equations or even cubic equations, and they were all worried about the calculation. However, Liu Meng, who was only in elementary school at that time, quickly gave the answer. The reason was that he had not learned any equations yet, but he did not have any complex equations at all. He used the principle of the smallest common multiple in elementary school.

Thinking of the anecdotes when he was a child, Liu Meng couldn't help but smile. Because of this, he was labeled as a genius in the village. The old man who set the questions concluded that Liu Meng would definitely make great achievements in the future.
Chapter completed!