In the twentieth century, Zhao Yun's class is nothing at all, and the content he talks about today can be mastered even by elementary school students, and even the students here have white hair and white beards. Pen @ fun @ pavilion wWw. ｂｉｑUｇE。 ｉｎｆｏ

Seeing that Mr. was bowing, the students instantly panicked, how did this make it?

No one took the lead, and they stood up one by one, and even the students outside the window no longer hesitated.

They stood respectfully, then bowed their noble heads and bowed silently to the one standing on the podium.

Maybe some people are like college students in later generations, looking for jobs in order to get a diploma, of course, their jobs are arranged by the emperor, which is an iron rice bowl.

As Mr. Zhao said in "The Teacher Said": A teacher, so preaching, teaching, and solving doubts, no one will have an opinion if he can be a teacher respected by a great man.

Legend has it that Fu Xi created the "rules" for painting circles and the "moments" for drawing squares, and it is also said that the Yellow Emperor's courtiers are the founders of "rules" and "standards".

As early as when Yu controlled the water, Yu was "left standard" and "right rule". Therefore, we can say that "rules", "rules", "standards", and "ropes" are the earliest mathematical tools used by our ancestors.

Measuring the area of the land, measuring the height of mountains and valleys, calculating the amount of yield, exchanging corn, and formulating the calendar all require mathematical knowledge.

"Zhou Ji Sutra" carries Shang Gao's answer to Zhou Gong's question, mentioning that the use of moments to measure the depth and breadth of the distance. According to legend, in the early years of the Western Zhou Dynasty, mathematics became one of the six compulsory courses in the education of aristocratic children.

However, at that time, the development of mathematics was quite slow.

During the Spring and Autumn Period, with the advent of iron tools and the improvement of productivity, China began the transition from slavery to feudalism.

The new relations of production have naturally promoted the development and progress of science and technology.

At this time, the royal power was declining, the people were scattered, and private learning began to appear. At the latest, in the late Spring and Autumn period, people had mastered the complete decimal position value notation, and the advanced calculation tool of arithmetic chips was widely used.

People are already familiar with the ninety-nine multiplication table, the four rules of integer operations, and the use of fractions.

During the Warring States period, the vassal states successively completed the transition to feudalism.

There are many scholars in the ideological and academic circles, and a hundred schools of thought are contending and are extremely active, creating good conditions for the development of mathematics and science and technology.

Although none of the pre-Qin mathematical works have survived to future generations, people have accumulated a great deal of mathematical knowledge through production and life practices such as the measurement of fields and land area, the exchange of corn, the harvest and the distribution of spoils, the construction of cities, the design of water conservancy projects, the reasonable burden of taxes, the calculation of yields, and the measurement of altimetry and telescope.

At the beginning of the Eastern Han Dynasty, Zheng Zhong recorded that the mathematical knowledge at that time was divided into nine parts: Fangtian, Corn, Difference, Shaoguang, Shanggong, Average Loss, Equation, Winning Deficit, and Side, which were called "Nine Numbers".

Nine Numbers establishes the basic framework of the Nine Chapters of Arithmetic.

Qin Shi Huang put an end to the strife of the nations and established a centralized feudal empire for the first time, which was supposed to be conducive to the development of mathematics. But his **** policy suffocated the academic air of a hundred schools of thought.

The brutal rule of the Qin Dynasty, especially the burning of books and the pit of Confucianism, caused unprecedented havoc on Chinese culture.

Soon, Liu Bang, the founder of our Han Dynasty, took advantage of the peasant uprising that overthrew the tyrannical Qin to unify China and establish the Han Dynasty.

The Han government and the people's livelihood were closely related, and the social productive forces were restored and developed, which brought new vitality to the development of mathematics and science and technology.

At the same time, people pay attention to the collection and sorting of pre-Qin cultural classics. As the crystallization of the new development of mathematics and the rescue of pre-Qin classics, it is the completion of the book "Nine Chapters of Arithmetic".

Mr. Zhao's lecture was at a relatively flat time at this time, and he was introducing the history of arithmetic.

"Today, I want to introduce you to a senior with high moral integrity." Zhao Yun's words surprised the students again.

After all, every teacher will not be on the same stage when they are lecturing, and it is not the cross talk of later generations.

"He is a descendant of Liu Xing, the king of Lu, the nephew of Emperor Xiaoguangwu of the Han Dynasty, and has received a good education since childhood. As a young man, he served as a lieutenant and had a special interest in the astronomical calendar. ”

"In the third year of Yanxi, because his literacy in the astronomical calendar gradually became known to the world, he was transferred to the institution in charge of the time and ephemeris, and he was the Langzhong of the Taishi Department."

"In the following 10 years, he actively engaged in astronomical observation and research, which laid a solid foundation for his later attainments in astronomical calendars."

"During this period, he worked with Mr. Cai Bojiao and others to determine five different astronomical data, including the position of the sun between the stars during the 24 solar terms, the distance of the sun from the arc of the celestial sphere, the shadow length of the sun in the middle of the day, the length of day and night, and the value of the 28 degrees in the middle of the sky at dusk."

"These observations are listed in a table and included in the Eastern Han Dynasty Quadrangular Calendar, according to which the above five astronomical quantities can be calculated separately by the one-time difference interpolation method."

Since then, these tables of astronomical data and their calculations have gone down in history and become the calendar of our country. He was involved in the important work of pioneering this new field, which was his first contribution to the world of astronomical calendars. ”

"In the third year of Xiping, he was transferred out of Luoyang and served as the governor of Changshan, his hometown, to assist Wang Guoxiang in handling government affairs."

"In the same year, he presented the work "Seven Yao Techniques" after years of research, which attracted the attention of the imperial court, and now the Holy Lord has specially issued an edict to appoint officials from the Taishi Department to verify the actual technique.

"According to the results of the verification, he revised the "Seven Yao Techniques" and wrote the "Eight Yuan Techniques".

"The two techniques are a treatise on the study of the movement of the sun, the moon, and the five stars, and are his early works on the calendar."

In the fourth to sixth year of Xiping, he resigned from his official position and stayed at home for 3 years because of his father's death. It was during this period that he completed his Nine Chapters of Arithmetic, a mathematical work that annotated the classic mathematical masterpiece of the same name and incorporated his research experience. ”

"Therefore he was known for his mastery of arithmetic, and for this reason he was appointed as the chief of financial affairs after the expiration of his filial piety."

"In the first year of Guanghe, he was Langzhong again."

"Because of his high attainments in astronomical calculus, he was recommended by Mr. Jiayue Bojiao to go to Dongguan and Jiayue to compile the Eastern Han Dynasty Chronicles together."

"Jia Yue is good at writing and communicating with music, he is proficient in calendar theory and secret arithmetic, the two complement each other's advantages, work closely together, and accomplish this task excellently."

In this year, he also put forward the idea of reforming the Eastern Han Dynasty four-minute calendar that was in use at that time, and for this reason, he first tested the solar eclipse: the solar eclipse is in Yan, the extra time is in the Chen, the eclipse is from the bottom to the top, and the three points invade two. After the fact, it was as he said. ”

"Although his proposal to change the calendar was not realized for various reasons, he was the most popular astronomer of the time."

"Last year, he was 50 years old, and because he had been raised to be a filial and honest person, and because he was dignified, rigorous, and sociable, he was appointed as a confessor."

Soon after, he moved to the post of Marquis of Guchengmen, one of the 12 gates in Luoyang at that time, located due north, and he was the supervisor of the gate. In this year, he presided over the review of the work of the feeding cycle proposed by Wang Han. ”

"This year, he also participated in the debate between Feng Sui and Zong Cheng on the lunar eclipse forecast and the eclipse cycle, and he judged it fairly with his profound knowledge and insightful insights."

Zhao Yun is a little narcissistic, because in his own explanation, even he was infected.

An old man with a long beard in the front row was even more excited with tears, ignoring etiquette, and frequently wiped his tears with his sleeves.

"After talking for a long time, you must be curious, who is he? He is Mr. Liu Hong and Liu Yuanzhuo, Marquis of Guchengmen! ”

Zhao Yun slowly saluted, and Liu Hong stood up silently. (To be continued.) )