Late night, flora.
The time is when most of the children are in bed and ready for bedtime stories.
There are almost people on the winding stone road, and camphor and low shrubs are planted all over the roadside, and mint and geranium are planted in the lower places. The night wind is blowing, and there is a faint fragrance of plants in the air
Street lamps cast a soft halo. Lao Lin led the 12 children behind him on this peaceful path for a walk.
Apart from…
"Master, there is no moon, how can the night be good?" Lin Zhaoxi looked around for a long time, and finally asked.
"Yeah, no moon."
"Neither are the stars."
"It's so dark."
The children were chattering, and the adults standing at the front stopped in embarrassment, and the quiet and peaceful atmosphere was instantly broken.
Lao Lin coughed a few times: "There is a moon in my heart, there is a moon everywhere, such a good day..."
"You should still talk about mathematics." Hanamaki interrupted him.
"What's so good about mathematics..." Lao Lin's enthusiasm for poetry recitation was hit again, "What do you want to hear?"
"Application questions!"
"That's right, the exam is coming up on Monday, the teacher will talk about the application questions, what's the secret?"
Lao Lin smiled, patted the child's head, and said unwillingly, "It's good if you want to learn word problems so much. Let's talk about numbers?"
"Ah~" the children dragged their tunes, "That's super boring."
"That's right, especially the prime numbers, decompose the prime factors." A boy from the sixth group said.
Hearing this, Lao Lin's eyes lit up: "It's incredible, you know so much!" He turned his head and nodded the one with the loudest voice: "Let's talk about what is a prime number?"
"A natural number greater than 1, except for 1 and itself, which cannot be divisible by other natural numbers is called a prime number." The little boy recited it very smoothly.
Thinking of a certain scene in front of the wooden door under the starry sky, Lin Zhaoxi couldn't help but sweat for this little friend.
"Yes, what is a natural number?"
Another kid answered: "It's 123456789 and there are many integers behind it!"
Lao Lin: "How much is a lot?"
"Infinitely many!" The child raised his hand and spread it, as if he was about to fly under the night sky.
Time and space seemed to stand still for a short time. Lao Lin stood under the street lamp, flying insects danced lightly above his head, he was smiling, and there were very faint lines at the corners of his eyes, but they seemed to be shining.
It was also at that moment that Lin Zhaoxi knew very well that Lao Lin was very happy. Compared with spending his days in the park, he preferred being with the children, and he also preferred the feeling of being close to mathematics again.
Lao Lin smiled for a while before slowly opening his mouth: "At the end of the 19th century, the Italian mathematician Peano proposed five axioms to define natural numbers. Let me recite them to you. One,..."
One, two, three, four, five, he recited the five axioms so handsomely that all the children thought they had heard a foreign language and had no idea what he was talking about.
Looking at these faces, Lao Lin asked, "Do you know what natural numbers are?"
"I don't know!" The children shook their heads in unison.
"Because there's a world of difference between reciting those five sentences and knowing what they are."
The students nodded vigorously: "So the endorsement is not important!"
Lao Lin smiled: "On the contrary, my point is that it is more important to understand. So, now let's take a closer look at what is called a natural number..."
Lao Lin pointed to the trees on the side of the road and began to tell the children what the most basic natural numbers are.
—
The path of the botanical garden is very long, but it is also very short, just like this from the beginning to the end, the small white building standing at the bottom of the mountain is already close at hand.
A group of them stood in the middle of the road, looking at the small dormitory building, but none of them wanted to leave.
"Go back to sleep early." Lao Lin broke the silence and turned to leave.
"I don't want to sleep yet!"
"You haven't finished the lecture just now, and you don't have time to learn tomorrow!"
"The exam is coming soon, and the questions are not done yet. You have to give us a lecture."
The students began to whisper again, and the voices of 12 children chirping together were very penetrating at night.
Lao Lin didn't care about them, he just left.
At this time, whoever had the guts said, "We'll run out after checking the room?"
"That's right, there is no class tomorrow anyway, and Auntie has come once and won't come a second time. I was found last time because the flashlight fell out..."
Lin Zhaoxi followed the reputation and found that it was Lu Zhihao who said it. She took a breath: "Old Lu, your thinking is too dangerous."
You were obviously the one who was caught by Vice Principal Zhang last time and was severely punished.
But the children don't care so much, they discussed for a while, considering that the school hours are too tight, and according to the current progress, there is no way to finish the study before the mid-term exam, so running out at night is really a feasible idea.
"Teacher, are you okay?"
I don't know who yelled, and I don't know who started to charge first. Lao Lin stood at the back of the downhill and stopped, and was soon surrounded by a group of students. Some people grabbed their clothes and others hugged their arms. In short, they just refused to let them go.
Lin Zhaoxi looked away, only to find that she and Pei Zhi were still standing there. They looked at each other and laughed in unison.
—
"I'll just say one thing." Lao Lin sat cross-legged on the mat, "I've been arrested, don't confess me."
There is light smoke in the room and the smell of mosquito coils in the air, but when it is quiet, you can also hear the sound of insects and frogs outside the house.
At night, they quietly came to Lao Lin's temporary dormitory.
The oasis base has no other advantages, except that there are many houses, so the dormitory for temporary workers like Lao Lin is actually a rare single room.
The place is big, but there are not so many tables and chairs, so the diligent little girls mopped the floor, and they sat on the floor tiles.
And Lao Lin was sitting next to the mosquito coils, and his whole person was set off with a fairy air.
"I remember just now, you don't like doing topics related to number theory?"
"Yes, I just think it's useless to learn this!" The student said, and started flipping through the book, "For example, this topic-there are 30 2-cent coins and 8 5-cent coins, and there are 49 different coins within 5 cents. Currency value, which currency values cannot be composed of the above 38 coins"
"Indeed." Lao Lin smiled: "Then why isn't it boring?"
"I... I think the word problems are interesting!"
Lao Lin smiled: "I think chickens and rabbits in the same cage are boring. Is it true that you count chickens and rabbits when you buy vegetables?"
The students have never seen a teacher who said that what he taught was boring, and began to be choked again.
"Many people will definitely tell you that mathematics is very beautiful, and they are widely used in daily life, but when we look down, what, they are all very boring topics."
"Yes, yes!" the children agreed.
Lao Lin: "That's why adults are lying to you, don't believe them."
Lin Zhaoxi: "..."
"Again, most mathematicians study mathematics because..."
"They're boring~" Hanamaki replied cooperatively.
"Yes, but if there weren't so many boring people, our current world would certainly not be what you see." Lao Lin sat up straight, full of energy.
He said: "Just now you mentioned prime numbers. The research on prime numbers can be traced back to more than 2,000 years ago or even earlier. What is a prime number and why should we learn it, still feel very at a loss, right?"
"Yes, yes."
The children soon became Lao Lin's answerers.
"Don't you feel bored if you have to know the meaning?" Lao Lin's tone was thought-provoking. "I can probably tell that there are two types of necessity in the study of prime numbers. Do you need to listen?"
"Yes, yes!"
"Primes are building blocks all numbers." Lao Lin said, "This is one of the sayings."
The children looked up at him, like staring little goldfish, very confused.
"Ah, teacher, what did you say?" Someone finally responded.
"Teacher, can you speak Chinese?" Chen Chengcheng asked weakly.
Lao Lin: "Children, it is very important to learn a foreign language well."
Lin Zhaoxi: ...
Lao Lin: "Come on, let me roughly translate it like this. Prime numbers are the basic elements that make up natural numbers. For example, scientists are always exploring what constitutes matter, molecules, atoms, and what is the subdivision of atoms?"
"what is it?"
Lao Lin: "I don't know, there is a saying 'string'?"
"Are prime numbers to natural numbers what strings are to matter?" asked a child who responded quickly.
"Because a prime number is indivisible except 1 and itself, it is super important to natural numbers!" An Beibei also shouted.
"I know that blocks are bricks. You just said that prime numbers are the bricks that make up natural numbers!" another child said.
The surprised smile on Lao Lin's face grew thicker and thicker: "Your English is really good, kid!"
The children were expressing their opinions one by one, and there were voices one after another in the dormitory. Lao Lin just listened patiently, nodding in approval to each child's answer, without criticizing. On this topic alone, they discussed it for half an hour.
Starting from the most simple prime number topic, Lao Lin explained different types of prime number topics to the children in a simple and simple way, and expanded from prime number to number theory. It seems that because of the discussion just now, number theory, a boring thing of pure mathematics, has become important in an instant. stand up.
After an unknown period of time, a child suddenly thought of something and asked, "What about the second meaning of prime numbers?"
Lao Lin smiled, as if he had waited a long time for them to ask this question: "Mathematicians have been studying prime numbers boringly for more than two thousand years. The distribution law of prime numbers, calculating how many prime numbers there are within a certain range... "
"How long does that take?"
"I don't know how long it took, it might be someone's life." Lao Lin smiled, "In short, they are struggling with these boring numbers. For more than two thousand years, mathematicians have been doing this kind of seemingly I can't find anything useful at all."
The children fell silent and looked at Lao Lin quietly.
"You ask what's the point, I don't think they know the point, they're just having fun."
"Live a poor life and have some fun." Lao Lin smiled. "It was not until more than two thousand years later, when human beings entered the information age, that prime numbers showed a little bit of their role. They were applied to public key cryptography systems. The current information security."
When Lao Lin said this, he stopped. The children nodded with half understanding.
Lin Zhaoxi looked at her father's smiling face while waiting, and she actually knew that what Lao Lin wanted to say was that there was no need to look for so many meanings, mathematics research itself was the meaning.
But he didn't say that, he probably hoped that the children would experience this by themselves.
Plant a small seed in your heart, maybe one day, it will grow into a towering tree.
Old Lin probably hoped so.
—
The study of the day went on very late, and it can even be said to be very early.
When sneaking out of Lao Lin's dormitory, the children were not at all tired. They walked quietly together at night, communicating casually, talking about topics they didn't know, what they learned today, and where they were going tomorrow...
Lao Lin followed at the end, and Lin Zhaoxi walked beside him.
Lin Zhaoxi raised her head and looked at the dark night sky. The air was humid, with the fragrance of flowers and plants, um... the fragrance of knowledge. She found a very literary metaphor.
"Girl." Suddenly, Lao Lin called her, "Do you want to go home tomorrow?" Lao Lin asked.
Lin Zhaoxi turned her head abruptly, and looked up at Lao Lin in a daze: "Big... I probably won't come back..."
"That's good." Lao Lin turned his head and asked Pei Zhi, "What about you, kid?"
Pei Zhi turned to look at him, very simply: "I won't return."
"That's not bad, Lao Lin smiled, "Take you guys for a picnic tomorrow? "
Lin Chaoxi was flattered and nodded vigorously. She happily turned her head to look at Pei Zhi, only to find that Pei Zhi's little classmate was looking at her thoughtfully.
As if to say, can you really do it tomorrow
Lin Zhaoxi suddenly remembered that phone call, the dean's mother said... weekend... Professor Shen and his wife...
After Lao Lin asked, he walked away with his hands behind his back, pretending that nothing happened.
Lin Zhaoxi's scalp was numb, what if Professor Shen and his wife brought Lin Aimin to visit her tomorrow