My life skills in Daming Liver

It was Chen Moqun, the head of Yanping Academy, and his friend He Liangjun, Mr. Tuohu, who rushed to Changningwei.

After the two entered Changning Guard, they found out that Su Ze was going to Zhangtian beside Jianxi at the entrance of the village. Anxious He Liangjun directly pulled Chen Moqun out of Changning Guard to look for Su Ze by Jianxi.

At this time, Lin Liangjun, the little carrot head, was instructing other children to measure the acres of fields. These are new fields that were opened up with the silt dug out after the construction of the creek.

The silt at the bottom of the river is rich in nutrients, so the floodplain has been the cradle of human civilization since ancient times. The Nile River, which often floods, fed the ancient Egyptians. The flooding of the river is both a destruction and a new life for civilization.

These fields are close to the river, and as long as they are leveled, they are high-quality paddy fields.

Su Ze asked the little radish heads to clear the fields and draw detailed maps. Another purpose was to plan and design irrigation water conservancy facilities.

For children of Xiaoluotou's age, being able to take classes outdoors is the happiest thing.

Since the awakening of mathematics skills, Su Ze has added mathematics courses in addition to the original enlightenment learning courses.

Calculating the area of ​​the field naturally does not refer to these children, but it is no problem to ask them to measure and draw a map. Lin Liangjun directed the children to pull the tape measure and record while measuring.

He Liangjun hadn't seen such a childlike scene for a long time. He recalled his hometown, Songjiang Mansion before the Japanese Invasion, and the fields were full of children running in early summer.

Regarding the current situation, He Liangjun was powerless to complain. The imperial court has suppressed the Japanese for so many years, and the more the Japanese were suppressed, the more serious it became. Even the dignified Songjiang Mansion was poisoned by Japanese pirates.

I didn't expect to see such a paradise on the coast of Fujian.

He Liangjun stepped forward and watched an airy child instructing other children to measure the length, while he wrote and drew on the paper with a charcoal pencil, and marked the measured length on the paper.

Seeing the charcoal pencil in Little Luobotou's hand, He Liangjun asked with interest: "Little baby, what is this?"

Little Luobotou looked at Chen Moqun and He Liangjun, and saw the students and guards following behind them.

Although Xiaoluotou is mischievous, he is also the son of hundreds of households in the guard, and he has some knowledge, knowing that these two people have a good background.

Anyway, holding back his temper, he said, "You two elders, this is a charcoal pencil."

Charcoal pens are actually pencils, and Daming has already started using graphite to make ink.

And some working people found that graphite can be used to leave marks on many objects. The earliest people who used charcoal pencils were carpenters and stonemasons.

However, the charcoal pencil in Xiaoluotou's hand was modified by Su Ze. He ground the graphite into a cylindrical shape, then put it on a thin reed rod, and then wrapped it with rags to tie it tightly, just like a modern pencil.

He Liangjun looked at the symbols and Arabic numerals on the paper and asked, "What is this word?"

Little Luobotou said: "This is a number."

He Liangjun stroked his beard and said, "Numbers? Interesting, this is very similar to Suzhou code, but it is more suitable for writing horizontally."

He Liangjun found out that the numbers written by Xiaoluotou were all written horizontally, and he probably understood the usage of this kind of numbers. The Arabic numerals written horizontally are indeed easier to read than the Suzhou codes written vertically.

Mathematicians before the Song Dynasty in China used calculations, and when recording numbers, they also used a symbol called Suzhou code.

Suzhou codes are written in the same way as Arabic numerals, which are simplified numeral symbols, and it is very convenient to use in conjunction with planning. He Liangjun also has property in his family, and the numbers on the ledger are also recorded in Suzhou codes.

After the abacus appeared, calculations gradually withdrew from the stage of history, and horizontal writing with pens was more convenient for calculations. Therefore, in the late Qing Dynasty, Arabic numerals completely replaced Suzhou codes and became the "numbers" common throughout the country.

When Su Ze checked the account for Yu Zongyuan, the number used in the account book was "Suzhou Code".

Su Ze studied modern mathematics, and the mathematical formulas he memorized were also modern formulas. Anyway, for mathematics, numbers are just symbols, so what he taught the little radish heads were also Arabic numerals.

He Liangjun looked at the little radish head writing and drawing on the paper, and he could see that he was in Qingzhang's field. He was also very surprised. The children in Changningwei also know how to do math?

Chen Moqun is the head of Yanping Academy. He looked at the picture drawn by Xiaoluotou, and the dimensions were clearly marked.

Chen Moqun said to He Liangjun: "I heard that Su Rulin set up a health school in Changningwei. These children should be his disciples."

He Liangjun stroked his beard and said, "In Jiaohua Township, there are scholars."

Chen Moqun also nodded. Although he didn't like Su Ze very much, Su Ze's teaching children to read in the countryside was very suitable for him, and it was also in line with the political correctness of literati and bureaucrats.

Chen Moqun became interested, and asked a few basic questions casually, and a group of children like Xiaoluobotou could answer them fluently. Now he is more satisfied with Su Ze.

He Liangjun couldn't help but sigh with emotion, this Su Ze is really not an ordinary scholar.

Su Ze, who got the news, saw the mighty follower team of the two, and knew that it was a big shot from the county.

When he found He and Chen, He Liangjun was asking Lin Liangjun about arithmetic.

"You don't even understand the coordinates? Take Tianyuan as the center and use the second line of latitude and longitude to determine the point position. Using this method, the area of ​​the field can naturally be calculated."

Little Luobotou found that He Liangjun was approachable, and soon forgot his respect for scholars, and began to yell at He Liangjun, showing off the knowledge of analytic geometry taught by Su Ze a while ago.

In fact, Little Luobotou only learned a little bit, but He Liangjun was attracted by this calculation method.

He is a famous dramatist and a bibliophile who loves books. All scholars in the Ming Dynasty had the ambition to be polymaths.

He Liangjun is very interested in analytic geometry. Using this method to measure the field is definitely much more convenient and accurate than the division and sum method.

Land buying and selling is also very frequent in southern Jiangsu, and the most important thing in land buying and selling is the area of ​​acres.

Therefore, when buying and selling among the people, scholars who are proficient in arithmetic are often invited to calculate the area of ​​​​the field.

A scholar who can quickly and accurately calculate the area of ​​​​the field, the income is also quite high.

In addition to liking opera, He Liangjun also likes to do research on mathematics. He used to buy and sell land. He Liangjun measured and calculated the land by himself, but the method he used seemed to be not as good as the method Xiaoluotou said.

But little luotou only knows the method of establishing a coordinate system, and the answer is all calculated by his hard-won formula.

The two discussed for a long time, but He Liangjun couldn't figure out how to calculate the area.

Su Ze knew Chen Moqun, he stepped forward to greet him and said, "I have met Mr. Chen Shan."

Su Ze didn't understand why Chen Shanzhang of Yanping Academy wanted to find him, but since he came, Su Ze also treated him with courtesy.

After Chen Moqun replied, he pulled He Liangjun and said to Su Ze: "Su Rulin, this is my friend He Yuanlang, named Mr. Tuohu, he is the one who wants to find you today."

He Liangjun was about the same age as Chen Moqun, with a gray beard and a Confucian hat, he looked like a celebrity.

But at this time, He Liangjun's appearance was not at all famous, his hands were covered with toner, and his beard was messed up because of thinking about Zhang Tian's calculation problems.

It turned out that it was Mr. Tuohu who was recruiting dramas in Yanping Mansion, and Su Ze also saluted He Liangjun.

He Liangjun pulled Su Ze and said, "Su Rulin, is this child your disciple?"

"I am a teacher of Wei Xuemeng, and I just enlighten these children."

"The Zhangtian method that this child learned was taught by you? Can you clear up the old man's doubts?"

Su Ze looked at He Liangjun suspiciously, aren't you a famous opera artist? How did you become interested in mathematics?

He Liangjun couldn't wait to say: "The child said that after the coordinate system is established, the area of ​​the field can be calculated through the formula. What is the principle?"

What Su Ze taught Xiaoluotou was the calculation formula of the shoelace theorem, which can be used to roughly calculate the area of ​​a polygon, but Xiaoluotou only knows the formula and does not know the specific calculation principle.

He Liangjun also used the division and summation method to check the calculation, and the answer was similar to the result calculated by the little radish headgear formula.

Moreover, Su Ze's method is faster and more convenient, as long as children know the formula, they can calculate it.

The Gaussian shoelace formula, also known as the Gaussian area formula, is a mathematical algorithm for finding the area of ​​a simple polygon of a defined area.

This is the original question. The principle of the Gaussian shoelace formula is actually very simple, which is to divide the polygon into multiple triangles, and then calculate the areas of these triangles separately.

Gauss further formulated this method, giving a formula that can roughly calculate the area as long as the coordinates of the vertices are known.

In fact, in the late Ming Dynasty, folks also invented a method with the same principle, which is called push step gathering top technique in arithmetic books.

After listening to the principle of Su Ze's formula, He Liangjun verified it with a charcoal pencil, and said in admiration, "It's wonderful! It's wonderful! Su Rulin is really a genius in mathematics for inventing this algorithm!"

Chen Moqun knew his friend's arithmetic attainments. He couldn't understand the algorithm explained by Su Ze and He Liangjun just now. He just nodded mechanically. He Liangjun said he was a genius, so he must be a genius.

Su Ze was wondering, did these two old men come all the way from the county just to discuss arithmetic with him?

He Liangjun finally remembered the business, and he said to Su Ze: "Ru Lin, you wrote the article "Du Shiniang Sinks the Treasure Chest in Anger" in "Surprised by the Case", right?"

It turned out that it was for this article, Su Ze said with a smile: "Mr. Hui Tuohu, it was written by late students."

He Liangjun said: "Well, this old man wants to change "Du Shiniang Sinks the Treasure Box in Anger" into a play and let the troupe rehearse it. What do you think Ru Lin thinks?"

Su Ze frowned and said, "I'm afraid I won't be able to catch the eyes of Mr. Tuohu if I don't understand rhythm and rhyme at a late age."

He Liangjun said hastily: "I'm here for the adaptation, and I'm also here for the rehearsal."

Seeing that Su Ze didn't immediately agree, He Liangjun said again: "Ru Lin, don't worry, you are still the author of this play, the old man is only in charge of adapting and arranging the music, and you will be the number one in this essay contest. How about silver as your touch-up fee?"

One hundred taels of silver!

Su Ze's eyes lit up! Otherwise, it is still easy for scholars to make money! An article is one hundred taels of silver!

For the authorization of an adaptation, these two old men came to Changningwei. Did the Ming Dynasty still have few pirates and plagiarism?

Su Ze quickly figured it out. Du Shiniang's angry sinking of the treasure chest was published in the tabloid. Now everyone in Nanping City knows that Su Ze wrote the article.

If He Liangjun adapted the play without Su Ze's authorization, he would definitely be cast aside by the scholars in the city.

Su Ze now understands the importance of controlling public opinion. Although "Surprise" is still a tabloid sold in Nanping, it has already made rich gentry like Chen Moqun and He Liangjun afraid of snatching Su Ze's articles at will. , but also respectfully spend money to buy Su Ze's adaptation authorization.

It's no wonder that Donglin Academy in the late Ming Dynasty had such a great reputation. If you control the public opinion, you can control everything!

Su Ze became more firm in his idea of ​​running a newspaper. "Surprise" not only needs to be run, but also become a national newspaper in the whole province!

Su Ze agreed, and He Liangjun also relaxed. He is very confident in the story of "Du Shiniang Sinks the Treasure Box in Anger", just like a famous director who has found the best script, and he is confident to produce a famous one. The play is out!

"It's hot in the field, the two gentlemen should go to Changningwei to sit down."

Someone rushed to give money, so Su Ze naturally showed hospitality and invited the two to sit in Changningwei.

The sun was getting hotter, and Chen He was a little tired, so he followed Su Ze to Changningwei.

Looking at the young children who were repairing ditches in the field and measuring the fields, Chen Moqun asked, "Why does Ru Lin want to measure the fields? Could it be that this is newly opened land?"

Su Ze nodded and said, "A few days ago, Changning Guard cleaned up Jianxi and opened up some new land. The guard is making a record."

Chen Moqun looked at Jianxi in surprise. They also went east along Jianxi when they came to Changningwei. The reason is that the water conservancy has just been repaired.

Su Ze explained the method of flushing the sand with beams of water again, and now Chen Moqun understood the principle.

The principles of physics are often simple and easy to understand. In later generations, the physics questions of the college entrance examination are still discussed every year, but no one cares about the math questions.

Unexpectedly, Su Ze would be able to repair water conservancy projects, He Liangjun had a higher opinion of him, and even Chen Moqun felt that Su Ze was a talent.

It is the political correctness of the scholars to govern the country and the world by regulating the family and benefiting the village.

After arriving at Changning Wei School, Su Ze took the two of them to visit the Wei School. Chen Shanchang generously donated some books and the Four Treasures of the Study to Changning Wei School.

For these two angel investors who had just invested money, Su Ze ordered Lin Cainiang to kill chickens and pick vegetables, and entertained the two of them graciously.

At the same time, Nanping County.

Huang Shixing stood expectantly in front of He Liangjun's door, and finally got the news from the door.

"What, Mr. Tuohu is traveling?"

"Where did you go? Changning Wei?"

ps1:

step-up technique

Under the microscope, the algorithm of Daming and Shuai Jiamo Zhangtian.

It's a good show, I recommend it

ps2:

Suzhou code, 〡〢〣〤〥〦〧〨〩ten, is still used in some areas today.

After checking the information, the mathematics of the Ming Dynasty is indeed not bad, which is a pity.