After the end of the day's deliberations, Liu He rarely returned to be generous, and invited everyone to eat together at the largest Tong Kee beef and mutton restaurant in Macheng, which was regarded as a reward and celebration.

Despite the small size of this mutton restaurant and its humble location, it is quite famous in Malaysia, and it is usually full of diners, and it is often necessary to make a reservation a few days in advance. This beef and mutton restaurant was the first to launch copper shabu shabu hot pot under the guidance of Liu He, and later other restaurants in Macheng saw that Tong Kee's business was booming, so they followed suit and popularized the eating method of copper hot pot. Because Tong Ji was personally instructed by the eldest prince, diners from the past came to visit, so business has always been the most prosperous.

The beef and mutton used in the Tong Ji Beef and Mutton Restaurant are all purchased from the Saiwaihu people, and they are freshly killed and cooked every day, so they are delicious and full of praise. In Youzhou, the slaughter of live cattle must be reported to the government, and if it is a bullock that can go to the land to plow the field, it must not be killed, otherwise it is illegal. The beef sold in the Tongji Beef and Mutton Restaurant is all beef cattle purchased from Wuhuan and Xianbei people, and they have undergone strict inspections before entering the city, so everyone can eat with confidence.

The reason why Liu He encouraged and advocated the people to eat beef and mutton in Macheng was not only for the consideration of improving the purchasing power of the mutual market, but also for the idea of improving the dietary structure of the people in Youzhou and improving the people's physique.

The mutual market in Macheng is the largest of the several border markets in Youzhou, and although Youzhou is in a state of hostility with the nomads of the north, it does not restrict the movement and trade of caravans between the north and the south. In addition to restricting merchants from carrying prohibited materials such as standard weapons, arrows, and copper, daily necessities such as salt, grain, herbs, and cloth produced in Youzhou can be traded on the mutual market.

Since the beef and mutton hot pot became popular in Youzhou, the Han people's demand for beef and mutton has increased year by year, and the price of cattle and sheep brought to the mutual market by the Hu caravans in the north has also risen significantly, which has made them earn a lot, so they can take away more urgently needed goods when they go back.

At first glance, it seems that the Han people have suffered a loss. But in the long run, it is actually conducive to border stability. Because the selling price of the livestock is rising, the Xianbei, Wuhuan and Xiongnu tribes in the north can settle down a little, and they will not think about going south to plunder every year, which also reduces the defensive pressure on Youzhou a lot.

Liu He's current strength is not enough to completely deal with the nomads in the north with the power of one state, so it is always advantageous to fight for more peace time on the border, after all, time is on Liu He's side.

After drinking and eating, everyone returned to the captain's mansion under the escort of the guards, and Xu Yue, who was already impatient, finally couldn't help but remind Liu He and said, "Son, before coming to Macheng." You said that you had a very ingenious invention for me, and I don't know when it will be cashed in after a month? ”

Liu He was a little drunk, and said to everyone with a red face: "It just so happens that everyone is here today, so I will uncover the mystery and let you see the same artifact!" ”

After Liu He said this, he turned his head and motioned to Xu Huang, and quickly took out the good things he had made. Xu Huang took the order, turned around and walked out of the door. After a while, he returned with a sandalwood box more than three feet long and one foot wide.

Xu Huang placed the wooden box flat on a long case in the middle of the hall, then carefully opened the lid of the box, and took out a rectangular copper frame with hundreds of round, black beads in the frame, and then placed it in front of everyone.

The brass bezel glows warmly under the oil lamp. The black lacquered beads are fixed in the copper frame by the copper pillar that passes through the middle, and the rows are so neatly arranged that people can see the fine workmanship at a glance.

Liu He was silent, and picked up a pointed wooden pole as thin as a little finger from the wooden box. Then he quickly listed a long list of numbers on the paper, and then looked up and said to everyone: "This is a set of number problems that need to be added, subtracted, multiplied and divided, so please do the math together!" ”

Only then did everyone realize that the wooden pen in Liu He's hand could actually mark light black marks on the paper. Although it is not as thick as ink, it is enough to make people separate, and it is obviously a substitute for writing with a brush.

This thing that was picked up by Xu Huang is naturally a common abacus for later generations. There is no technical difficulty in making this thing, the key is to have design sketches and ideas, with the craftsman skills of the Han Dynasty at this time, it is not difficult to make a copper abacus for Liu He, that is, to create a pure gold abacus.

In the last time and space in which Liu He once lived, he began to contact the abacus when he was in the third grade of primary school, and was forced by his mother to recite the abacus formula with a broomstick, and later participated in the abacus competition organized by the township, and then represented the township to participate in the abacus competition for primary school students in the county, and finally won the second prize. Later, after going to high school and college, Liu He played with the computer, but the abacus ability of the three years of intensive training when he was a child had not been completely lost, so he not only instructed the craftsman to secretly make the abacus this time, but also recalled some basic abacus formulas and wrote them down on paper.

As for the "wooden pen" that appeared with this abacus, it was also a simplified version of the pencil made by Liu He after he had his craftsmen try it out again and again. Don't look at this thing is smaller than the abacus, but the process of testing and making is much more troublesome than the abacus, just adjusting the mixing ratio of toner and clay took Liu He a lot of effort.

Although the writing with a brush is beautiful and beautiful, it is obviously too cumbersome for shorthand and arithmetic, while the pencil, although not as good as a fountain pen, does not wet the paper, and the carbon element does not fade, the writing is smooth, and the paper is not picky at all. Youzhou is still using rough, yellowed, fragile Caihou paper, although Liu He knows the production process of a little white paper, but has not had time to practice, it is estimated that it will take a while to really launch.

Although I don't know what Liu He's intentions are, since Liu He has a request, everyone learns Liu He in turn to pick up a wooden pen about seven inches long from the wooden box, stand in a circle around the long case, and bury their heads in calculations.

The people in the house are Liu He's henchmen, and now they have all learned Arabic numerals and column vertical arithmetic, except for Xu Huang who is not very proficient, even Zhao Yun is fluent in writing, which shows that Liu He's teaching in this area is not divided into civil and military, and has achieved results.

When everyone was immersed in calculations, Liu He quickly played with the abacus with his right hand, and there were words in his mouth: "Seven up two go five into one...... Nine back one return five go to four ...... 21 Add 5...... Every four into ten ......"

After a while, Liu He wrote down the results of the calculation on paper, while the others were still working hard.

Xu Yue, the only one in the field who didn't move, stared at Liu He like looking at a monster at this time, and he whispered softly: "It's incredible!" Xu has been pondering how to make an arithmetic tool to replace the complicated and cumbersome arithmetic chip in the past few years, and today I saw this arithmetic artifact designed by Childe, and I felt like I was familiar at first sight and suddenly enlightened! ”

Liu He was secretly happy in his heart, this thing was originally invented by you, a great mathematician, is it good! I just let the abacus come out more than ten years in advance, and when you look at it, you naturally feel like you are familiar at first sight, and you suddenly open up......

Liu He handed Xu Yue a few pieces of paper that were flat in the abacus box, and then said with a flat face: "It's not unusual to make this thing, what is really valuable is these pieces of paper, if you take a closer look, you can understand the mystery." ”

Xu Yue excitedly stretched out his hands, picked up the abacus formula from Liu He's hand, and looked at it intently.

"Wonderful! What a second to mention! Xu Yue, who had finished reading the mantra, couldn't help but let out an exclamation.

As a math master in the late Han Dynasty, Xu Yue quickly discovered the law of the abacus formula without Liu He's explanation, and he naturally understood the meaning and value of these thin pieces of paper.

After another while, Guo Jia, Liu Fang, Han Heng, Liu Hui, Zhao Yun, Du Ji, Xu Huang and others successively calculated the problem that Liu He arbitrarily came up with including four operations of addition, subtraction, multiplication and division through the vertical method.

Fortunately, although the speed of everyone's calculation is fast or slow, the result is the same as Liu He's calculation, and there is no "ugliness" on the spot.

When Liu He dialed the abacus beads just now, he was by everyone's side, so at this time, everyone had already understood the effect of this thing similar to "calculation chips" in front of them.

"I named this thing 'abacus', which is a shortcut tool specially used for various calculations, as long as you memorize the mantra of the operation, and then after a few days to half a month of repeated practice, even if you are a ten-year-old child, you can be several times faster than an adult who has a very smart mind but does not use an abacus!" Liu He proudly introduced the abacus to everyone.

Guo Jia carefully stroked the abacus beads with his hand with a serious face, and said with emotion: "Childe's mind and calculation are really amazing to our generation!" In the future, Youzhou will have the artifact of the abacus, which can not only save a lot of manpower and time, but also make the circulation of goods faster, make all matters involving calculations simple for the government and the people, and enable the logistics officers in the army to better ensure the supply...... There are so many benefits that abacus can bring! ”

Liu Hui said with some complaints: "Childe, since you have such a treasure hidden in your heart, why didn't you make it a few years earlier and teach us?" It hurts how much sleep the old man has slept in the past few years, and he is tired of gray hair! ”

......Everyone in the hall laughed loudly and deeply agreed with Liu Hui's statement.

After laughing, Liu He solemnly put the abacus, calculation formulas and simple charcoal pens into the box, and then sent them to Xu Yue, saying: "Today I will send this abacus to Mr. Gonghe as a commemoration, I hope that Mr. can help me and cultivate a group of talents who are proficient in calculation for Youzhou and Dahan!" ”

Xu Yue took the wooden box, nodded and said: "Don't worry, as long as Childe doesn't think that arithmetic is the last skill of the side, the contemptible people will definitely do their best to give their students what they have learned all their lives, so that I will have a few more arithmetic masters in the future!" (To be continued......)