When Liu Xin returned to the room, he found that the table was full of chips. Pen % fun % Pavilion www.biquge.info

Arithmetic is a unique ancient Chinese notation, which follows the decimal system, and represents the number of units in two vertical and horizontal arrangements.

According to the records of historical books and the discovery of archaeological materials, the ancient arithmetic chips are actually small sticks of the same length and thickness, generally 13 to 14cm long, 0.2~0.3cm in diameter, mostly made of bamboo, but also made of wood, animal bones, ivory, metal and other materials, about 270 pieces for a bunch, put in a cloth bag, tied around the waist to carry around.

When you need to count and calculate, you can take them out and put them on the table, on the kang or on the ground to fiddle with, but don't look at these are inconspicuous small sticks, but they have made great contributions in the history of Chinese mathematics, such as Zu Chongzhi when calculating pi, he used to calculate the chip.

The calculation chip in front of Zhuge Zhan is a set of wooden calculation chips, which is used in the Huangfu accounting room.

Liu Xin saw that Zhuge Zhan had no more calculations, so he knew that he had already calculated the answer.

So Liu Xin said with a smile: "Siyuan, it seems that you have already calculated the answer." ”

Zhuge Zhan didn't have the joy of calculating the answer, but nodded a little depressedly, and said: "Yes, my lord, I have already calculated the answer, it is 4662 taels of gold." ”

Liu Xin smiled, nodded and said, "The answer is correct, but why do you look sullen?" ”

Zhuge Zhan sighed and said helplessly: "I originally planned to solve this problem by mental arithmetic, but after thinking about it for a long time, I didn't come up with a reason, and finally I had to choose to use the arithmetic chip, but it took almost half an hour to solve this problem, I feel a little ashamed, and I am sorry for the trust of the lord." ”

Liu Xin nodded, Zhuge Zhan was able to admit his shortcomings, indicating that he was still a manufacturable material.

Liu Xin took a piece of blank paper and a pen, and said with a smile: "Siyuan, do you believe me, I will use this pen and paper to calculate the answer to this question in half a minute?" ”

Zhuge Zhan frowned, he didn't believe that he could calculate such a complex topic with just paper and pen.

However, Liu Xin didn't care, and wrote the multiplication formula of the problem directly on the paper, but it took more than ten seconds to get the answer.

Zhuge Zhan looked at the answers on the paper and the calculation process that seemed to be understood, a little surprised, and a little incredulous.

Qin Mi next to him also came over, looked at the calculation process and answers on the paper, pondered for a moment, and said with some doubts: "Lord, are you using the ninety-nine multiplication formula?" ”

Ninety-nine multiplication formulas, multiplication formulas that primary school students must learn today, have long existed in ancient China.

"Pipe: Light and Heavy" finally has a cloud: "The filter opera is made to make six mountains to welcome yin and yang, and the number of ninety-nine is to be in line with the way of heaven." ”

It is also recorded in "Han Poems Biography", "Qi Huan set up a banquet in the court, and he did not wait for people, and there were people who saw it with ninety-nine." ”

However, the ancient multiplication formula is from top to bottom, starting from "ninety-nine-eighty-one" and ending with "one-to-one", its order is the opposite of the modern ninety-nine multiplication table, because the ancients used the two words "ninety-nine" at the beginning of the multiplication formula as the name of this formula, so it is called the ninety-nine multiplication table.

Zhuge Zhan came to his senses at this time, completely understood the operation process on the paper, and couldn't help admiring: "The lord is talented, I have always felt that the ninety-nine multiplication formula is just a rigid formula, and the lord can actually expand the ninety-nine multiplication formula to form a new calculation method, and I am convinced." ”

Liu Xin smiled, shook his head and said: "This calculation method is called multiplication, which is specially used to calculate the total amount of several people with the same number and then add up, it is a branch of the four operations, and it is a calculation method that my master Zhou Gong has spent many years to understand, as long as you learn this calculation method, or the way of thinking, even if it is a yellow-mouthed child, you can calculate faster and more accurately than an old account office for decades." ”

Qin Mi and Zhuge Zhan nodded thoughtfully, although what Liu Xin said was very simple, but for Qin Mi and the two of them who were in contact with multiplication for the first time, it was like opening the door to a new world, which was enough for the two of them to explore for a long time.

Liu Xin smiled, and followed the example of a primary school teacher, and introduced the concept of the four operations to Qin Mi and the others in simple terms, as well as their respective calculation processes.

As mentioned earlier, Qin Mi and Zhuge Zhan were only limited by the limitations of the times, which led to the limitations of their thinking, so they could not solve problems with multiplicative thinking, and could only calculate through calculations.

But Qin Mi and Zhuge Zhan's intelligence is beyond doubt, but in a quarter of an hour, under the guidance of Liu Xin, Qin Mi and the two understood the essence of the four operations, and easily answered the new questions raised by Liu Xin.

Qin Mi couldn't help but sigh: "These four operations are simply magical, and the calculation chips are simply the light of rice grains in front of the four operations, how can they compete with the sun and the moon." ”

Zhuge Zhan also shook his head with a wry smile, and said to Liu Xin: "Lord Dacai, I used to sit in a well and watch the sky, self-righteous, thinking that my arithmetic ability can become the first in Yizhou, but now I think about it and feel ridiculous." ”

Liu Xin smiled, and then said seriously: "This is not your lack of ability, but a limitation of thinking, your way of thinking has been besieged by the wisdom of your predecessors, so the first thing that comes to mind when calculating is to calculate chips, even if the chips will be very troublesome when calculating some problems, but I have not thought of using new methods to solve them." ”

Qin Mi and the others lowered their heads a little ashamedly, as Liu Xin said, their way of thinking has been limited by the wisdom of their predecessors, and they think that the knowledge summarized by their predecessors is the most correct and convenient.

Liu Xin stood up, patted Qin Mi and Zhuge Zhan on the shoulders, and said seriously: "The predecessors planted trees, and the descendants enjoyed the shade, but we also have to think about our descendants, should this tree be pruned, or a few more trees, so we have to look at old things with a critical eye, old knowledge, and also to discover new shining points in old things, what do you say?" ”

Liu Xin recalled the content of the high school politics teacher's class, and taught Qin Mi and the others a good lesson.

Qin Mi and Zhuge Zhan looked at Liu Xin with an unclear expression.

Liu Xin felt that his image was a lot taller in an instant.

ps: The second update, continue to ask for favorites and recommendations.