The banquet was still going on in the splendid palace, and Li Er was sitting on a high seat, his face was red, and he didn't know if it was because he had drunk a lot of wine.

"Grandpa, I've come up with something interesting these days and want to dedicate it to Grandpa." Suddenly, Li Tai walked out and looked at the princes with a smug face.

Li Tai is no worse than Li Chengqian now, and the most favored princes in the entire Tang Dynasty are their two brothers.

"Oh? What is my son's magnum opus? Li Er said with a smile, Li Tai just presented "The Chronicles of the Universe" some time ago, and it was in the limelight for a while, which made Li Shimin very happy.

The son has a future, and he is naturally very happy to be a father.

In the Tang Dynasty, the titles of 'Father' and 'Mother' have not yet appeared, and in the Tang Dynasty, it is estimated that it will be regarded as hysteria, and then a group of imperial doctors will study around you all day long, so Li Tai is generally called Li Shimin 'Grandpa' or 'Father'.

"Grandpa, this is a new method of arithmetic that I recently researched with the doctors of the Chongwen Pavilion, which is simple and full of mysteries." Lee Tae said with a look of pride on his face, then spread out a piece of cloth and began his performance.

"Grandpa, these strange symbols are actually what we often call 'zero, one, two, three, four, five', each symbol corresponds to a number......" Li Tai gushed out, talking about Arabic numerals and addition, subtraction, multiplication and division.

Cheng Chubi's brows furrowed slightly, isn't this the Arabic numeral that he popularized in Princess Xinping's mansion? Does this guy know anything? It's strange, this thing shouldn't have been circulated from Princess Xinping's mansion yet, right?

"Isn't that your Arabic numerals? How did this guy know? Damn, he's taking your stuff for himself! Chai Lingyu saw Li Tai excitedly explaining, and his eyes couldn't help revealing a strong disgust and anger.

Cheng Chubi gently patted Chai Lingyu's hand, smiled faintly, and said in a low voice: "Don't be angry, don't be angry, it's not good to be angry." ”

"But they robbed you of what you had, and it was yours. You are the inventor and owner of these numbers! The anger in Chai Lingyu's eyes was even stronger, if it weren't for Li Tai being his cousin, with Chai Lingyu's irascible temper, he would have stabbed him into a hole with an iron spear a long time ago.

"My stuff? No, no, no, you misunderstood, the Arabic numerals were not invented by me, they were created by the Tianzhu ancients as early as the Northern and Southern Dynasties, and the real owners of these numbers should be the Tianzhu people. It's just a synthesis of the things of the ancients, and besides, how can anyone take away what I got if they want to? The smile on the corner of Cheng Chubi's mouth became even stronger: "Now Li Tai actually said that he invented it, wait a few days, hehehehehe......"

The smile on Cheng Chubi's face became even stronger, how can Lao Tzu's things be what you want? Even if you are Wei Wangtai, you can't do it! After a while, there will be a headache for Li Tai.

At this time, Li Chengqian's whole face was cold and terrifying, his hands were clenched tightly into fists, and he seemed to be eager to step forward and beat this guy fiercely. And Li Ke's face was also quite bad, frowning and drinking the wine in the cup.

"Your Majesty, Wei Wangtai's method of counting is really strange, and it is convenient to calculate, and I ask Your Majesty to order it to be widely promoted, especially the multiplication formula, if you learn it well, even an illiterate person can understand the method of calculation." An old man stood up and said, this person is none other than Kong Yingda, the contemporary family of the famous Kong family, a great Confucian in the world.

"Your Majesty, King Wei's method of arithmetic is the first method of arithmetic in the world, and it should be promoted!" After Kong Yingda finished speaking, another very famous person stood up, it was Xiao Yu, this old man is not simple, but the seventh son of Emperor Xiao Yue of Liang Ming of the Southern Dynasty, the half-brother of Emperor Xiao Cong of the late Liang Dynasty, and the brother of Empress Xiao.

"Okay, since that's the case, then tomorrow we will start teaching from Guozijian and Tai Academy, and then promote it to the whole country, Li Tai listens to the order, and from tomorrow onwards, you will be an assistant teacher of Guozijian and Tai Academy, teaching arithmetic." Li Er said with a smile.

"Thank you, Your Majesty!" Li Tai couldn't help but show his excitement, the teaching assistant work of this era is similar to that of later generations, but the identity is different, the teaching assistant of this era is an official from the sixth grade. Emperor Wu of the Western Jin Dynasty established Guozi in Xianning, and was the first assistant professor to assist doctors in teaching students. The Northern and Southern Dynasties, Sui and Tang dynasties were set along the line. In the Tang Dynasty, Guozixue, Taixue, Guangwenguan, Simenguan, etc., also set up teaching assistants.

This is capital, although the official quality is not big, but Li Tai doesn't care, the students in these places of Guozixue and Taixue will all be state officials in the future, and now he can enter these to teach them arithmetic, so that he can easily win people's hearts and minds, which is quite beneficial to the struggle for the throne.

"Your Majesty, this method of arithmetic has no name yet, please give it a name." Li Tai said.

"Then let's call it Zhenguanjutsu!" Li Er said happily, Cheng Chubi below rolled his eyes when he heard it, Arabic numerals were taken by you father and son like this, but at this time, the Arabs had not invaded India, and the title Arabic numerals had not yet appeared.

"Your Majesty's name is good."

"The art of Zhenguan, if this technique can be promoted, it will be beneficial to all aspects of Datang."

"The art is the face of the prosperous age."

“……”

"Zheng Zheng Zheng ......" sounded one after another when everyone patted Li Er's fart, as if there were thousands of troops galloping on horses.

"What kind of fun is this, so magnificent?" Cheng Chubi couldn't help asking.

"King Qin's Broken Array Music!" Chai Lingyu said.

"It turned out to be music praising Li Er, no wonder it's so majestic." Cheng Chubi nodded secretly, but at this time, Li Er happily stood up from his seat, ran to the middle of the crowd and jumped up, followed by Cheng Yanjin, Wei Chigong, Niu Jinda and other generals, and even Fang Mou Du Duan jumped up.

Cheng Chubi was suddenly scorched by thunder on the outside and tender on the inside, what is the situation? Could this be the legendary Datang Square Dance? In fact, the Tang Dynasty is an era of singing and dancing, and many people in the Li Tang royal family are famous literary and artistic workers.

In the dead of night, everyone dispersed the banquet and left the palace in twos and threes. Chai Lingyu and Cheng Chubi rode horses and returned to Princess Xinping with a team of female soldiers. The guards and Qubu of the princess's mansion are all women, and I don't know if it's because Chai Lingyu is a female general.

"Whoosh!"

As he was walking forward, suddenly, a bowstring sounded, and a sharp arrow broke through the air and went straight to Cheng Chubi's head.