In the room, Xian Ning and several researchers who were usually responsible for teaching the children took the math curriculum compiled by Jiang Xingchen and slowly flipped through it, while the old man was holding a piece of paper next to him, scratching his ears and cheeks, and thinking about it for a long time.

"Xingchen, isn't it too easy to start with numbers, children should all know!" After reading two pages, Xian Ning raised his head and asked. Several other researchers nodded their heads.

"It's simple, but the foundation must be laid! You continue to look back!" Jiang Xingchen smiled.

Xian Ning didn't say much, continued to look back, turned two more pages, his eyes lit up, and he sighed. This is followed by the classification of numbers, as well as the practical meaning of numbers in life, and then the basic addition and subtraction, addition and subtraction within a hundred, examples of practical meaning, multiplication and division...... Then there are the four rules of operations and the laws of arithmetic, the interchange of decimal and fractions, operations, the division of generals, and simple graphs......

Of course, Xian Ning knew all these things, but it was definitely not as systematic as Jiang Xingchen summarized, and it was clear and clear, step by step.

Several other researchers also showed solemn expressions, having such a systematic set of things is too important for children's enlightenment.

Looking further back, Xian Ning suddenly frowned and asked, "Xingchen, what is a negative number?"

"A negative number is a number below zero!" replied Jiang Xingchen.

∧

"Below zero?" Xian Ning muttered, still not quite understanding, and asked again, "Is there any practical significance?"

Jiang Xingchen thought for a moment and said, "Take our Xingchen Collar as an example, the back mountain is more than 100 meters above the ground! But Qingshan Village is in a low-lying place at the foot of the back mountain, and if we survey the terrain, we will conclude that Qingshan Village is below the ground. So we use the ground as the dividing line. You can record Qingshan Village as minus how many meters!"

"Also, when we settle accounts. Profits can be recorded as positive and losses can be recorded as negative!

"Got it!" listened to two examples. Xian Ning finally came to an avail.

"Sir, why didn't you say it earlier if you have this method! Every time I look at my watch, I have to check it carefully several times!" It was Grandpa Fu who said this, and at some point, he also came to the house, and happened to hear Jiang Xingchen explain negative numbers.

Jiang Xingchen smiled and didn't speak, letting Xian Ning and the others continue to watch. Further on are some quantitative relationships summarized by Jiang Xingchen. Such as time, speed, distance. Unit price. Quantity, total price. Work efficiency, working hours, total amount of work, and so on. Then there's the issue of concentration, the question of profit......

Xian Ning and a few researchers nodded again and again, these summaries are very useful when solving practical problems.

Further back are squares, triangles, rectangles. Calculation of these areas of trapezoids...... The greatest common divisor and the least common multiple!

When they got here, it was a little difficult, Xian Ning and several researchers didn't understand, and Jiang Xingchen explained them carefully. And use a question to explain the practical application of least common multiples.

It's just an old lady going out. Someone accidentally touched it, and all the wild pheasant eggs in the back basket were broken. When people want to pay, the old lady doesn't know the total. I only know that this basket of eggs is two or two and counts one, and three and three counts and one is left. Four fours count one left, five five counts one left. Six six counts are left with one, and seven seven numbers are just right.

"I'll go, there is still this kind of question?" I don't know when, Jiang Xingchen's room was already surrounded by a bunch of people, all watching Jiang Xingchen's explanation. And it was Zhao Danqing who screamed.

Jiang Xingchen looked up and was startled, and saw Zhao Danqing, the second brother, the fourth, Grandpa Fu, and Nier all gathered around him, crowded to the ground.

"Why are you all here?" Jiang Xingchen asked.

"We came to play cards with the old man, and we just happened to see you talking here! I said brother, how did you come up with such a murderous topic?" Zhao Danqing said loudly, and the second brother and the fourth brother next to him nodded again and again.

Jiang Xingchen smiled: "Is this question difficult?"

"It's not difficult, it's not difficult, I'm stunned when I look at it!"

"Hehe! This is still difficult, you go and see the old man's question!" Jiang Xingchen stretched out his hand and pointed to the back.

Zhao Danqing and the others looked in the direction of their fingers, and saw the old man squatting there, grabbing his hair and thinking about it.

"Flutter!" the three of them couldn't hold back, and burst out laughing at the time. What I know is that the old man is thinking about the question, and those who don't know think that he is constipated and holding back, and his face is out of shape.

"I'll go, what's so powerful, torture him like this!" Zhao Danqing muttered and walked over. The second brother and the fourth brother glanced at each other and followed.

"Old man, what are you thinking about, so serious?" Zhao Danqing squatted beside the old man.

"Don't affect me, play mahjong and find someone else!" said the old man angrily. Now he's holding his breath.

Today, he came to Jiang Xingchen to ask Tang Chuxue what Cheng dù had practiced in Tai Chi, and he was originally very happy. As a result, when I saw the math on the table, I picked it up and flipped through two pages.

He was used to messing with Jiang Xingchen, and when he saw how simple it was on the first few pages, he couldn't help but say a few words of sarcasm. As a result, Xiao Soul Dan threw such a question, and said that it was done by children under the age of ten, so let himself try.

Then he held it until now, obviously looking simple, but he couldn't think of an answer.

"Gotta go, I'll go, I'll go, you think slowly, let's find someone else!" Zhao Danqing said with a smile and waved his hand.

But just as he was about to leave, the old man suddenly said, "Wait a while, Zhao boy, do you want to see this question?"

At this time, the old man reversed his appearance just now, and smiled so much that the wrinkles on his face came out.

"No, no, I didn't want to see it!" Zhao Danqing hurriedly waved his hand, and when he saw the smile of this old thing, he knew that he didn't have any good intentions, he knew too well after being in contact for so long.

"I didn't want to see you ask me what I was doing, come here!" the old man said, suddenly bursting out, without waiting for Zhao Danqing to react, he pulled him to his side, and the piece of paper with the title written on it was also sent to him.

The second brother and the fourth brother glanced at each other and hurriedly retreated, worried that they would also be affected.

However, they thought well, but the old man was already eyeing them, how could he let them run, and his hands stretched out like lightning and dragged them over.

"Three tourists came to Xingchen to live in the hotel, and asked for a total of three rooms, one for each person, and ten citrine coins for each room. Later, the shopkeeper felt that he had received too much, so he asked the man to return the five citrine coins to the three people. As a result, the guys were greedy, and each of them only returned one, leaving two for himself. The final question is that the three of them each spent ten coins and returned one, which is equivalent to spending nine citrine coins each. Thirty-nine is twenty-seven in total, and two of the guy's are twenty-nine. Where's the other citrine coin?"

This is the topic written on the paper, and Zhao Danqing and the three of them subconsciously read it according to the title after seeing it. Then I was dumbfounded, yes, there was still a citrine coin, why was it gone.

The tourist paid thirty, the shopkeeper returned five, and the guy returned three, which is indeed the three people who spent nine each, three nine and twenty-seven, plus two in the man's hand...... Oh I'll go, hell, why is there one missing!

The more the three of them thought about it, the more they couldn't figure it out, and after a while, they became the old man just now, holding his hair with his hands and a constipated expression.

The old man finally felt a little more comfortable in his heart, and sure enough, he still watched others suffer offended! But he turned his head to look at Jiang Xingchen, and his heart was awkward again, he didn't need to ask if it was this kid himself!

As soon as he thought of the question, he couldn't help but wonder again, where did that citrine coin go.......

When the four of them were in a daze here, the immortals around Jiang Xingchen were also pondering, it would be too troublesome to count them one by one.

"Put this question aside for a while, go back and be interested, you can think for yourself, you can make it with the least common multiple! Let's continue to look down!" Jiang Xingchen interrupted everyone.

Xian Ning nodded, and continued to look back, the following is the equation. This is a new concept.

"What's the equation?" asked Xian Ning, puzzled.

"It's a formula with unknowns!"

"Unknown?" Xian Ning frowned, these things summarized by Jiang Xingchen looked simple at first, but they became more and more difficult to understand later. For example, the area calculation formulas of those graphs are all strange symbols with abcsh or something, which are not easy to understand.

"That's right, it's unknown......" Jiang Xingchen thought about it and took out a classic question from the previous life, chickens and rabbits in the same cage.

Thirty-five heads, ninety-four legs, asked how many rabbits and how many chickens. Of course, Jiang Xingchen has to talk about wild pheasants!

This problem is not difficult, but to solve it with arithmetic, first you have to find the right idea, such as treating all the heads as rabbits.

But it is much easier to solve it by the method of equations, just let one of them be x, and the other is thirty-five minus x.

Sure enough, I have never done this question, and it is not easy to find ideas. Xian Ning and several researchers were all lost in thought.

Just when Jiang Xingchen was about to tell the method of the equation, suddenly Nier shouted, "I came up with it!"

The little girl's voice woke up Xian Ning and looked at her in surprise. Jiang Xingchen was also a little surprised, and asked, "Nier, you figured it out, how did you do it?"

"In this way, you can think of the cage as wild pheasants, then their legs are ......" The little girl picked up a pen and paper and began to write and draw on it.

The more Jiang Xingchen looked at it, the more surprised he became, this girl's solution was exactly the same as the arithmetic solution in the previous life.

"Sir, do you think I'm doing the right thing?" No, Nier put down her pen and said to Jiang Xingchen.

"That's right, this solution is right, Nier is amazing!" Jiang Xingchen rubbed Nier's head, and said secretly in his heart: "This girl is a little interesting!"

Nier was praised by Jiang Xingchen and laughed happily.

Xian Ning and the others took the problem solved by Nier and watched, and they couldn't help but sigh at this girl's whimsy.

Jiang Xingchen clapped his hands lightly and said, "Next, I will tell you that the solution of the equation is much simpler than Nier'......

Jiang Xingchen was saying this, when a burst of shouts suddenly came from his ears: "I don't want to, this citrine coin is going to go anywhere!" (to be continued......) R752