Chapter 3 discusses the N solutions of "chickens and rabbits in the same cage".

Dr. Zhao welcomed the eldest grandson into the side door and sat down in the hall. At this time, the eldest grandson Tang personally presented his father's eldest grandson Wuji's greeting post and gift list yesterday, and Dr. Zhao bowed his head slightly. At this time, his own subordinates took over the shackles in Zhang Zhong's hands and led Zhang Zhong to rest.

"The students came today, and the teachers were busy with affairs and had a lot of troubles, but the students were eager to seek teachers and look forward to Haihan." Without waiting for Dr. Zhao to speak, the eldest grandson said slightly apologetically.

"It's okay, it's okay, I don't think you can have a beginning and an end, stick to yourself, and be sincere!" Although he didn't laugh out loud, the smile on his face revealed Dr. Zhao's mood at this time.

"Students are ashamed." The eldest grandson admires his acting skills a little, a proper Oscar winner!

"Deserved, deserved. But why did you want to go into arithmetic? You must know that arithmetic is broad and profound, and many people can't know a thing or two from the poor scriptures. If you worship the three schools such as Guozi and Simen, with your hard work and tenacity, you will be able to understand the scriptures. As soon as the words came out, Dr. Zhao remembered the identity of the eldest grandson's concubine, maybe it was just the one who came to learn to be the bookkeeper, after all, the eldest grandson's greatest achievement may be to be in charge of the eldest grandson's mansion. Dr. Zhao's face couldn't help but sink.

The eldest grandson observed the words and looks, and saw that Dr. Zhao was slightly unhappy, and he had a plan in his heart, and immediately said: "Not long after my mother died, the eldest lady was deceived by the villain, and my example was reduced by ......"

Seeing that the eldest grandson was deep in thought, Dr. Zhao, who didn't know that he was playing the sad card, comforted: "It's been so long, your mother will be happy to know that you are now, mourn!" ”

The eldest grandson, who found that Dr. Zhao had a problem with his emotional intelligence, accepted it when he saw it, and continued: "At that time, I made up my mind to get rid of my problems and prepare to study hard. Uncle Zhang is my mother's family, and when he saw that I began to work hard, he began to save money to buy books for me, but he didn't understand how to read, he bought a lot of books, read a lot, but learned very little. It wasn't until one day that I heard Uncle Zhang and Aunt Zhang quarrel over this matter, and I found that I had no money, I didn't believe it, but I couldn't read the account book, so I planned to learn arithmetic. Uncle Zhang gritted his teeth and bought "Sun Tzu's Sutra" when he came back, and I was attracted by many questions in it. Have an idea of a few of the issues inside,"

"You said that you learned arithmetic with the book "Sun Tzu's Sutra"? What are the issues you have studied in the past? At this time, Dr. Zhao obviously had a tendency to go berserk, and the meaning of the eldest grandson was like a primary school student reading this calculus with relish, and he was ashamed to say that mathematics was too simple.

"I especially like the idea of chickens and rabbits in the same cage." The face of the eldest grandson was immune to this level of ridicule, and he said without hesitation this classic problem that later junior high school students knew to solve with a system of binary equations.

"Today there are pheasants and rabbits in the same cage, there are thirty-five heads on the top, and ninety-four feet on the bottom, ask the pheasants and rabbits how much they are?" Without waiting for Dr. Zhao to ask, the eldest grandson immediately said. In the Sutra, it is explained that the total number of the two is halved to obtain forty-seven, and forty-seven is half of the total number and there is another meaning, that is, the number of heads of the chicken is twice the number of rabbits, subtract thirty-five, and the remaining twelve is the number of heads of the figure, and the number of heads of the chicken is twenty-three. That's one of ......"

"Do you have any other algorithms?"

"In order to understand this problem, I raised a few chickens and rabbits, observed for many days, and found that the difference between the two is that the number of feet is inconsistent, and if the number of feet is the same, this problem will be solved."

"But how can the two be the same?"

"So I first tied the rabbit two legs together, and found that the number of feet at this time was seventy, and the total number of feet was subtracted from seventy to get twenty-four, and in the process of tying, each rabbit was less than two legs, so the number of rabbits was twelve." The eldest grandson stopped, and Dr. Zhao pondered.

"This question can be like this, it's amazing!" After a moment, Dr. Zhao sighed.

"There is another solution to this problem." Without waiting for Dr. Zhao to interject or ignore his astonished gaze, Changsun Tang continued: "If the number of chickens is assumed to be four, then there should be a full number of one hundred and forty, subtract ninety-four, and the remaining forty-six, and divide by two to make the number of chickens twenty-three. "Since it is installed, it must be a complete set, this is the truth pursued by the eldest grandson. Of course, with such a lofty method as the system of binary equations at the beginning of the later generations, this one time is finished, how to install it later?

Dr. Zhao was still immersed in the words of the eldest grandson and did not recall it, for himself, who had been influenced by Confucianism since childhood, this kind of statement that one is no longer one, and it can be assumed that it is two. He couldn't understand why, but Changsun Tang also came to the correct result, and used more than one result.

This is the early years of the Tang Dynasty, and his mind is still relatively open-minded, although he can't understand it, it doesn't prevent him from attaching importance to this kind of solution. He wanted to take his eldest grandson to the study to continue the discussion, but when he saw it, he found that the sky had darkened, and the days of the first month had begun to grow, but the low clouds and heavy snow blocked the light.

The eldest grandson said goodbye, and Dr. Zhao agreed to go to school on the first day of February.

When the eldest grandson came out, he saw that it was getting late, so he urged Zhang Zhong to go home. The snow never stopped, and by this time there was a thick layer of snow on the road, and the ruts crushed over the fluffy snow, making a creaking sound.

The eldest grandson leaned on the carriage of the carriage and floated into the distance with a cool thought.

It's been three years since I came here, and when I first arrived, because of the misdeeds of my predecessor, my mother, who was not in good health, became ill and died. His mother is the daughter of a former Sui high-ranking official, because her father was foolish and loyal, Emperor Yang of Sui was implicated after his death, Fu Bo protected his mother and went to Gao Shilian, the uncle of the eldest grandson Wuji, so as to get acquainted with the eldest grandson Wuji, the eldest grandson Wuji wanted to treat each other as a wife, but the Dou family did not allow it. And her mother sent people under the fence, and admired the talent of the eldest grandson Wuji, so she could only serve as a concubine, and soon gave birth to the eldest grandson. Maybe the eldest grandson also knew the status and future of the concubine, so he indulged himself, and the family let it go in order to prevent conflicts with the eldest son and eldest grandson. And the Dou family and several other houses continue to provoke incidents, crowd out and suppress, plus their son is not angry, and the mother Zhang family has a very hard time.

Passing by the East Market that was about to be curfew again, the hustle and bustle of the scene was still the same, pulling Changsun Tang's thoughts back, he watched the bustling crowd continue to pour out, disappearing into the flying snow and remembering today's half-truths and half-truths, as one of the traversals, what did Changsun Tang do in general? Rebellion, just think about it these days. As an official, he first had to pass the eldest son of the eldest grandson. In these years, concubines basically have no political rights. Doing business, no matter how good it is, it is also family's, unless you carry it out of the court, this, oh, forget it, the price will be too high to bear......