The Son of Heaven neither goes to court nor reads the recitals, and he does not see anyone all day long. But people still know where and what he is doing: there are so many people in Penglai Palace, and they have to take turns to eat and live in the dormitory waiting for Jincheng. Xue Chongxun did not do the work of the emperor, and temporarily changed his career to do the business of writing books and sayings.

The first is to write about mathematics, which is the foundation of a qiē science. He started with Arabic numerals, which were invented by the Indians and had them very early. Xue Chongxun felt sorry that Master Xuanzang went all the way to Tianzhu to retrieve the Buddhist scriptures, why didn't he bring back the Arabic numerals. This thing is very simple, but it is more suitable for mathematics than Chinese characters, and it is mainly convenient for formulas.

After the Buddhist scriptures were brought back to the Tang Dynasty, they were not localized, and many people went to the temple to pray to God and worship the Buddha very utilitarianly, in Xue Chongxun's view, those scriptures really did not play much of a practical role, but the Arabic numerals were very valuable. It's just that the Central Plains only attaches importance to the way of sages and sages, and doesn't pay much attention to this kind of thing.

The rules of Arabic numerals, including decimal points and four types of operation symbols, are very simple, and Xue Chongxun wrote them all within an hour. This kind of thing comes with text annotations, so the literati can understand it at a glance, so they don't have to worry about it at all. Isn't it pediatric for people who can read through the Four Books and Five Classics to comprehend these things? The ancients were obviously not as stupid as they thought.

Next is arithmetic, he doesn't have to write too much, everyone knows the algorithm of addition, subtraction, multiplication and division now, otherwise how did the abacus come out? Xue Chongxun only needs to give examples of various algorithms and use Arabic numeral columns.

By lunchtime he had finished writing such a large part, which was something for the bureaucratic literati to read, and could be described briefly without being repeated at length. If this kind of thing is to be used to compile teaching materials to teach children in the future, it is the business of the officials, and Xue Chongxun does not have to do it himself.

He hurriedly ate something, and began to concentrate on writing again, anyway, there were palace maids waiting for other things, and there was no need to do anything else. In the afternoon, he began to write algebra and plane geometry, and at the same time, he changed to another one when he was tired of writing. In terms of algebra, because of habits and convenience, it is still the use of letters, after all, it is a bit strange to be sandwiched in Arabic numerals, such as a is phonetic "eh", b is "than", it is just a symbol, and others will be able to see the habit of barrier-free.

Geometry is more troublesome, involving the problem of weights and measures, although Qin Shi Huang also re-stipulated the book with the text, the car with the track, but Xue Chongxun decided not to introduce the meter, decimeter after consideration, this kind of unit, anyway, zhang, ruler, inch are ready-made, the world also used habits to become a consensus, will be used is, left and right is a unit of measurement. Maybe China will develop in this area in the future, and others will think that the size unit will be more formal...... This thing is not a military secret, Xue Chongxun can issue a decree strictly prohibiting the disclosure of gunpowder and artillery manufacturing technology, but if other clans want to learn this thing, they can't keep it secret.

What equations, systems of equations, plane geometry proofs, equilateral equiangles, etc., are all simple things, Xue Chongxun forgot to sleep and eat, and wrote them all on the third day. It's just a few formulas and arguments, a little game for junior high school students.

On the third day, when it came to vectors, sets, and functions, and then analytic geometry and solid geometry, Xue Chongxun had a bit of a headache. I remember that in my previous life, I took more than 130 points in mathematics in the college entrance examination, and more than 280 in the science and science comprehensive exam, but after so much time, what I did at this time was not just to do questions, but mainly to describe the inferences of each formula clearly and convince others. It's a bit of a pain, it's a lot of work.

He also thought that more inferences in higher mathematics would be more of a headache, so he planned to only make calculus, and this relatively high-end content would not be included in the imperial examination. After all, advanced mathematics is the application of modern technology, and in the current environment, it has no practical value and can only be regarded as an intellectual game like Go.

Princess Jincheng's palace room was soon filled with all kinds of manuscript papers, which were thrown everywhere by Xue Chongxun. He is used to the life of opening his mouth and stretching out his hands for food, and his habit is to throw away a page after writing, thinking that someone is waiting to clean it up, but I don't know who dares to move the palace maids?

Most of them don't even know a single big word, and the formula in front of them is like a book from heaven in their eyes, in case the emperor can't find what he puts in the palace to blame, maybe he doesn't need his golden mouth, and the princess of Jincheng will have to pull out their skin.

When the palace maid who delivered the meal cautiously withdrew from the palace, she whispered, and one of the palace maids said, "What is the emperor writing, it's been many days." The other said: "Maybe it's counting the fortunes of heaven and the country, let's not talk too much." ”

Xue Chongxun inside had already said several times, "It's good to have a pencil", but everyone didn't know what a pencil was, so naturally there was nowhere to get it for him. Princess Jincheng asked Yu Liben, and Yu Liben was also unheard of.

The things that Xue Chongxun wrote, she understood them all in the early stage, starting from Arabic numerals, and the more complex formulas involved more formulas, and she couldn't remember all the formulas in a short time, so the reasoning process was in the clouds. However, she knew what Xue Chongxun was probably writing, as he said "mathematics".

He hasn't changed his clothes and bathed for almost ten days, his image is almost unkempt, others have to wait for him to bathe and change clothes, and he still wants to be angry. One day, when he was irritable, a palace maid accidentally provoked him, and he was directly ordered to pull him out and beat him, and he was beaten half to death. Except for eating, drinking, and sleeping, he spends his days tinkering with that thing. The Ministry of Internal Affairs also made all kinds of strange tools as required.

Jin Cheng is also quite depressed, although Xue Chongxun stays here all day long, but he doesn't sit and chat like before and cast heartwarming glances from time to time, but now she is completely like a wooden person, let alone go to the bath to peek at her bath. The palace was full of paper, and even the walls were pasted with various figures. And I don't know how long such days will last, and I can't see that Xue Chongxun has the intention of stopping writing.

The eunuch Yang Siqiao came to report that Du Xian continued to provoke a war in Yingzhou, led his troops from Yan County to attack Gebezhou, robbed and slaughtered tens of thousands of Hu people of all ethnic groups, and the courtiers were very dissatisfied that it was not conducive to stabilizing the border, and they piled up a lot of recitals to replace Du Xianam.

As a result, Xue Chongxun said: "I didn't lose the battle, what are you nervous about?" Isn't Gebezhou the territory of the former Tang Andong Protectorate, there is nothing wrong with taking it back, where is there so much trouble for Dongyi to surrender quickly? Du Xian is not a person who leads the troops for a day or two, and he is not a person who does not know the importance of the matter, he has his own measure. ”

Yang Simiao hurriedly persuaded: "When Du Xian was in the Western Regions, he only had 4,000 subordinates, so he dared to drive straight into the battle between Xiao Bolu and the Tubo army. Now with more than 100,000 soldiers and horses, I am afraid that the heart of opening up the territory is too serious, and I am a little lacking in long-term consideration. ”

"it." Xue Chongxun said, "Didn't the political affairs hall want Cheng Qianli to repair the city? After I think about this, it's not too late to change Du Xian. ”G