The position organization of Chongxian Pavilion is very simple, mainly with two bachelor's supervisors, that is, the positions held by Zhang Zong's father Zhang Jingzhi at that time. Under the bachelor's degree, there are several direct bachelor's degree. These bachelor's degree teaches different subjects, such as Bachelor's degree in Confucianism, Bachelor of Computing, Bachelor of Law, etc.

The bachelor who came to study in the afternoon was a tall and thin middle-aged man with a long face, a straight facial features, and a short beard. When he came, he held a stack of books in his hand. After he came in, he immediately introduced himself.

Only then did Zhang Zong realize that the gentleman's surname was Lu and his name was Chuan. Of course, in order to show respect, both the direct bachelor and the bachelor were called the bachelor. Then, the bachelor and the bachelor sent the books in his hand to Zhang Zong and others. Each person had ten copies, and each of them had different contents. The first one at the top was the famous "Nine Chapters of Arithmetic".

"Mathematics is a profound and profound science. The more you study it, the more you will feel your ignorance. After the founding of the Tang Dynasty, I compiled ten mathematical classics into volumes and became the textbooks of mathematical science in the Imperial College. That is, the ten books in your hands, including Nine Chapters of Arithmetic, Zhouren Mathematical Sutra, etc., collectively known as the Ten Books of Mathematical Sutra..."

Mr. Lu first introduced these ten textbooks, and the entire arithmetic course revolved around these ten books. When they finished learning all ten books, their arithmetic will be considered a master.

Zhang Zong and the other three were not just school children who were in the imperial examination and had a certain foundation in arithmetics, so Mr. Lu did not talk nonsense and started talking about the first book, which is the first chapter of Nine Chapters Arithmetic - "Fang Tian".

This was the first time Zhang Zong looked through Nine Chapters Arithmetic. After all, this was not taught in later schools. When he opened the book, he found that this famous mathematical masterpiece was actually more like an exercise collection, which was mostly used for actual mathematical problems, such as the proportional conversion of grain, calculation of earth and stone engineering, etc.

Of course, there is also some pure theoretical knowledge, such as the area calculation of various figures and the solution of equations. The last chapter explains the Pythagorean theorem very clearly. What is very interesting is that Zhang Zong discovered that the name "Equation" comes from Jiuzhe Arithmetic.

The first chapter of the square field explained by Mr. Lu is the calculation of the area of ​​various figures. In fact, this is also for practical purposes, mainly used to calculate the area of ​​fields. After all, the shape of fields is not regular. If the court wants to count the area of ​​fields, it must calculate them. The easiest way is to cut them into various calculating figures, which is also the source of the name of the chapter "Fangtian".

After hearing a few words, Zhang Zong frowned quickly. The calculation method Lu Xueshu said was fine. Even calculating the pi of the circle area was very accurate, and Zhang Zong could not find any fault at all.

But the only thing that Zhang Zong couldn't accept was that all calculation processes were written in Chinese characters, and simpler steps were nothing, but if there were more steps and the number of words was written, the final calculation process would look very complicated.

It is probably because of this reason that Jiuzhang only writes questions and answers in arithmetic, and omits the calculation process. If most people want to learn, they must be taught by the teacher. Otherwise, if you just read the book by yourself, you will probably be confused.

However, although the Tang Dynasty's mathematical science made Zhang Zong uncomfortable, he could at least understand it. Unlike Zhihuzhe in the morning, he also made people drowsy. After finishing his lecture, he left them a few questions and asked them to try to calculate. If there are any questions, he could also answer them in time.

These questions seem to be extremely simple. They are nothing more than a variant of the question in Fang Tian’s chapter, that is, the original question has changed a little number and expression, and the calculation process is basically no different, so he calculated it almost in the blink of an eye, and he used the method he just learned. The whole process is only expressed in Chinese characters.

However, after writing the calculation process, Zhang Zong became more and more awkward as he read it. In the end, he wrote the symbolic operation process of later generations next to it, and also commented on the meaning of each symbol representation.

"Huh?" The inspector Lu Xueshu quickly discovered the strange symbol operations in Zhang Zong's writings, which made him stand next to Zhang Zong in surprise, looking down at these strange symbols. Through the comments written by Zhang Zong next to him, he slowly understood Zhang Zong's calculation process.

"This... is what you think?" Soon, Master Lu picked up Zhang Zong's manuscript paper with shock and asked. He never dreamed that in this world, he could write the calculation process so simply.

"It's not true. Most of it was learned from books." Zhang Zong smiled and said. Mr. Lu was indeed a person who knew the goods and could see the value of symbolic operations at once.

"Extremely wonderful! Extremely wonderful!" The more Mr. Lu looked at the operations on paper, the more excited he was. Not to mention anything else, just adding, subtraction, multiplication and division, and simplifying the ten numbers 0 to 9, made the entire calculation process very clear. Especially Zhang Zong wrote the same problem-solving steps together, and you can see at a glance that using symbol calculations reduces most of the space, and the more complex the calculations, the simpler and easier to understand.

"Zhang Zong, which book did you learn the method? Can you lend me a look?" Mr. Lu immediately told Zhang Zong again.

"This... I am ashamed to say that there was a fire in my home a few years ago, and many books were burned, and that book was destroyed in the fire." Zhang Zong still used the fire to block the gun for himself.

"Mr. Lu, I can prove this. Brother Shi taught me that the use of these symbols was indeed much simpler than the previous calculation!" At this time, Xue Shao also stood up and said, and also sent his calculation process to Mr. Lu. He was very troublesome and used symbol operations directly, so that he could write most of the characters less.

"You all do?" Li Dan looked at the calculation process written by Zhang Zong and Xue Shao, but looked confused. He couldn't understand it at all, but since he was so respected by Master Lu, it was a very good method.

Seeing that Xue Shao also understood this symbolic operation and personally admitted that it was taught by Zhang Zong, this made Mr. Lu no longer doubt it. He immediately discussed the methods of these symbolic operation with Zhang Zong.

Zhang Zong did not hide his own personal information. Speaking of which, he rarely met someone who could discuss mathematical problems with him, so he also answered some questions raised by Mr. Lu one by one, and at the same time wrote down some mathematical theorems so that the other party could better understand.

Mr. Lu thought that Zhang Zong had only occasionally learned the novel and simple operation method of symbolic operations, but as the conversation deepened, he found that Zhang Zong's understanding of mathematics was far beyond his own. Many mathematical theorems that he had never heard of were told were told by the other party, and it was very difficult for him to understand.

In the end, Mr. Lu even explained the difficult questions that he had never been able to solve. As a result, Zhang Zong quickly gave the calculation method and answers. Mr. Lu was really shocked, and he was even a little ashamed that his achievements in mathematics were not as good as those of a teenager, which made him doubt what he had learned over the years?

However, no matter how ashamed, his enthusiasm for math quickly made Mr. Lu devote himself to it. He stopped giving lectures at this time, but sat cross-legged across from Zhang Zong, listening humbly to Zhang Zong's explanation of some difficult problems. The new knowledge and theorems used in it also made him fascinated, feeling that Zhang Zong helped him open a door again.

In fact, in terms of the depth of mathematical research, Zhang Zong may not be as good as Mr. Lu, but due to the limitations of the times, the knowledge structure of mathematicians such as Mr. Lu is generally not systematic. They may be very good at some aspects, but some aspects are their shortcomings.

In contrast, Zhang Zong has learned systematically, and later mathematics has already figured out a clear path through the efforts of mathematicians of all ages. This is exactly what Lu Xueshu and others lack the most. Every sentence and every word of Zhang Zong is like a ladder to him, helping him lay a more reliable foundation in mathematics.

Although the learning process is painful, if you really get into learning, you can experience endless happiness. For example, Li Dan can experience the joy of learning, which also makes time pass very quickly.

When Zhang Zong's two-dimensional quadratic equations were various solutions, the sky outside was already dark, and Xue Shao and Li Dan had long been unable to understand what they were talking about. At this time, they all sat aside bored, and their stomachs were so hungry that they were screaming.

Zhang Zong felt a little dry and stopped the discussion and said, "Mr. Lu, his mathematics is profound and profound, and he cannot be explained in one or two days. It's getting late now, so why not discuss it when you have time in the future?"

"This..." Mr. Lu was still unsatisfied, but when he looked up and saw the sky outside and the resentful eyes of Li Dan and Xue Shao, he knew that he had been delaying for too long, so he smiled embarrassedly, "I heard what Zhang Zong said today, it is better than what I have studied hard for ten years. The problems that I could not solve in your hands are almost solved."

When Mr. Lu said this, he showed a shameful expression again, and then he spoke and suggested: "Why not do this? Don't call me a bachelor's degree. I really have no face to teach you. In the future, we will discuss friendships with peers. Just call me Lu Chuan!"

"Mr. Lu is so polite. I have just read some miscellaneous books and know a lot of things. It is far less than that of Mr. Lu. You are in your math. In the future, we will still be a teacher and student, and we can discuss and learn from each other in our daily lives." Zhang Zong also hurriedly refused.

Seeing that Zhang Zong refused, Master Lu did not insist. After all, it was so late now. If you talk a few more words, Li Dan and Xue Shao next to you would be hungry, so he immediately announced that he would leave school.
Chapter completed!