"So, you were already planning to do this before you came to Shuntian Mansion?" Zu Dashou sat at the table and looked at Yang Fan who was eating tofu brain.

Yang Fan sucked the tender tofu brain into his mouth, "It is impossible for one person's energy to be scattered in so many places, and so can one country." It's chaos inside and outside, is this still necessary? ”

"Yangzi." Zu Dashou said with a solemn face, "Don't delay a country because of personal gains and losses." Ancestor, I know you have the ability. It is definitely not an easy task to build the Daling River this time. The first two rush to build were all stirred up by Huang Taiji. This time, the Holy Lord ordered me to lead 10,000 Guanning Iron Cavalry, just to go and build the Daling River. It's a great time for you to make a difference! ”

Yang Fan pursed his lips, swept the remaining tofu brain into his mouth, and glanced at Zu Dashou, if he told him that there would be a vicious battle in the Daling River this time, and it was also 10,000 Guan Ning Iron Cavalry War Horses were lost, almost became a bunch of infantry, and was captured by Houjin, see if this old boy dares to take a step out of Shuntianfu.

Yang Fan put down the spoon and bowl and said, "Do you have any communication with Xu Guangqi?" ”

"My ancestor is a big and rough man, except for leading the troops to fight, he doesn't know a few words, Xu Lao is a scholarly family, a veteran of the Three Dynasties, how can he be communicative."

Yang Fan thought about it, too. It was really nice to let such a big old man and the crepe of the Ministry of Rites screw together, so he took out a pre-written letter from his arms and said: "My name is soft-spoken, and no one will pay attention to it even if I come to visit." If you send this letter in your name, you will be a general soldier, and people will sell you face. ”

"Boy, what are you doing to see Xu Lao if you have nothing to do? Now Xu Lao seems to be compiling some kind of calendar, and he is very busy, so you don't have nothing to do. Although my ancestor Dashou is a big man, he also knows that this work is not something that ordinary people can do. Your military talent is served by my ancestors, is it possible that you still have achievements in the astronomical calendar? ”

"Hmph, Lao Tzu will be a lot more. Do you send it or not? ”

Zu Dashou grabbed the letter and said, "Send, send." You kid has a bright brain, except for the stupid thing you did this morning, you can be considered half as intelligent as my ancestor......"

"Fuck you, uncle. Get lost! Yang Fan kicked Zu Dashou's ass and kicked him out of the room. In the first two months of his life in the countryside, he often bet with Zu Dashou on sand table drills, and this bet was almost all played from eating food to kicking his ass. Poor Zu Da has a life span of nearly half a hundred, and he has lost more times in the hands of Yang Fan than in half a lifetime combined.

Yang Fan is not afraid of him, Xu Guangqi is illiterate, and what is in the envelope is a world map that he personally drew the day before. As an undergraduate student who graduated from the Department of History, he won the first prize in the geography competition, and he drew a rough map of the world with his bare hands, which is not a novice for Yang Fan.

He believed that this map was a hundred times more accurate than the seventeenth-century map that Ricci had brought from the West! I'm not afraid that Xu Guangqi won't know the goods!

……

……

The next day, Zu Dashou said that he was going to hand over the military order, and he would dare to go to Daling River in a few days, and then he ran away without a trace. Tell Yang Fan to stay in the inn in peace for the past few days, and stop causing any more trouble. Yang Fan was still in a daze at that time, and he only heard the ancestor say that he was going to do business, and he directly ignored the miscellaneous words in the back.

Shuntianfu is so big, I haven't had a good look around. Yang Fan ate a bowl of tofu brain and left the inn.

In March, although the crisis in the capital has just been lifted, there are still many tourists who go out for a walk. Whether it's calm or war, life always goes on. Some people who heard Yang Fan talk about books at the dim sum stall yesterday came forward from time to time to inquire about the progress of the matter. Of course, Yang Fan is not good at telling the truth, so he can only say perfunctorily, and he is still reviewing and reviewing.

"Come on, get over it. Liu Qi, a master of arithmetic, set up a ring in Xianju Building again, and heard that he was going to meet the master of arithmetic in the capital for a while. ”

"What's so nice about arithmetic? Isn't it just a plan to play and compare hand speed? No, no, no. ”

The handsome man on the side held a small paper fan and said disdainfully: "I will die studying." Have you read Xu Lao's "Geometric Original"? Rush candle. ”

The man on the side scratched his ears and cheeks and recalled: "There is a book in the scriptures? ”

"Say you're going to die. This book was translated by Xu Lao from the foreigners, and all kinds of mysteries are endlessly interesting. Alas, I won't tell you, I'm going to see the fight. ”

"It's so amazing, that boy has to go and take a look."

Although Yang Fan is a liberal arts student, after all, he was trained in Greater China, and junior high school mathematics can directly crush other American high school students, not to mention the "Geometric Original". It's just some simple theorem.

What Yang Fan didn't expect was that in this year of imminent death, Eastern and Western cultures still exchanged so frequently. I only knew Xu Guangqi before, but now I understand that there is such a large group of people who are obsessed with different academics. He still followed, wanting to see how far Daming's arithmetic had developed, and if he could mention something, he would naturally mention it.

Well, to put it bluntly. I just want to pretend to be ...... Use the mathematics level of a Chinese undergraduate who has experienced the high school entrance examination to abuse those who are still studying trigonometric functions.

Upstairs in the Xianju, a huge four-foot large Xuan is painted with a lattice drawing, facing the door. A group of people gathered at the door of the Xianju Building, watching the liveliness. Of course, there are also people who are counting with pen and paper.

"How can it be done to fill in the number from one to eighty-one in the grid, so that the sum of each row and column is equal, and the sum of the two pairs of angles is equal to the former, this ...... How is this possible? ”

"When a talented person from Jiangdong came to Beijing to fight, he naturally made full preparations, how could it be a joke. People said that those who solved the three problems would set up a banquet in the Xianju Building for ten days. ”

Yang Fan knew at a glance that it was just a copy of the nine-square grid. If there is no way, it is estimated that you will not be able to make it up until you die. If it's one to nine, it's easy to make it up, but it's hard to do it with nine times nine squares. However, for Yang Fan, who suffered greatly from the Olympiad in primary school, this is all sprinkling, as long as there is time, the ninety-nine times ninety-nine square grid will be made for him. Use a Rob method and write it down according to the corresponding position, so you don't have to think about it at all.

Yang Fan found a big tree, bought a bag of bean halva, and ate it deliciously.

Some people have to put pen to paper, but there are too many things to consider. Some people first counted in a row, and then switched the positions before and after, and soon found that they looked at this side, and that side was wrong, and it was even more difficult to find two diagonals. Some people fill in the opposite corners first and make up the calculations.