Imperial College Kindergarten

Chapter 43 Ancient Arithmetic Problems

In class, Xue Bo puffed up his little chest and said loudly that the three of them had forgotten their homework at home. The other children turned to look at him. method!

Liu Xueting smiled secretly. It seems that throughout the ages, children who did not do their homework have always used the same excuse!
They obviously haven't realized the cruelty of this society.

Dr. Zhou nodded, skipped the three people, and asked the others to hand in their homework.

After all the homework was handed in, Dr. Zhou glanced at the people below and then checked them one by one without haste.

Mo Wuyou's eyes were full of admiration for his boss. Dr. Zhou actually believed it. The boss was so awesome!
Xue Bo waved his hand, these are nothing!
"There are some students!" Dr. Zhou was so angry that his beard flew up. "Some of them handed in blank papers! Some of them wrote on them that they couldn't read two characters! Some even drew a turtle on them!"

"What's going on?" Dr. Zhou pressed his homework on the teaching desk, "I think you all have to copy the garden rules again today! Xue Bo and the three of you, double the number!"

Xue Bo and the three of them were stunned!

"Looking at me, I don't know what you are thinking, hum! I was tired of these little tricks when I was a kid!"

At this time, Commander Yi spoke.

"Doctor, it's not that we don't write, it's just that we really can't."

"Don't you know how to ask others for advice? I remember that His Royal Highness was an outstanding student in the Taixue class!" Dr. Zhou sighed with a bit of hatred.

Unexpectedly, shame flashed across the face of the little princess: "Why do you have the nerve to ask others? Doesn't it reveal that I don't know how to do it?"

Dr. Zhou was visibly choked.

Immediately, everyone seemed to have opened their chat boxes and complained one after another.

"Come on, doctor, my brother said that arithmetic has always been a difficult subject in the Imperial College. Even in the Imperial College class, there are not many people who are proficient in it!"

"Yeah, even my sister in the beginner class can't solve this question!"

"Too difficult Doctor!"

"Is it difficult?" Dr. Zhou snorted heavily, "Listen carefully! If you pass this class, you still don't know how to do math and copy the garden rules!"

After that, Dr. Zhou used a special writing brush to write the title on the rice paper hanging behind his back.

"Today, there are people buying things together. Each person contributes eight coins, and there is a surplus of three coins. Each person contributes seven coins, and there is a shortage of four coins. Ask the number of people and the price of the goods."

"This type of question is relatively simple. It uses the over-deficient algorithm. The so-called over-deficit means to first list the yield rate. The yield rate is also called a false order. Then list the numbers of surplus and deficit. Make them consistent with what they are. Cross-multiply the resulting rates to achieve the same result. Let the resulting rates of multiplication be regarded as true. The sum of excess and insufficient is the law, and the true and true laws are unified, and the conclusion can be obtained!"

"Isn't this very simple!" Dr. Zhou touched his beard and then looked at everyone, but seeing that everyone was confused, he couldn't help but frowned, "You don't know how to do it yet?"

Everyone shook their heads.

Dr. Zhou was helpless, but considering that these little kids were still seven or eight years old, he became a little more patient and explained in detail again.

"Let's look at this question. The surplus is three and the deficit is four, right? To make the false orders consistent, we must make the surplus and the deficit the same. Therefore, the surplus and the deficit must be equal to what they are, you calculate!"

Some children began to count with their fingers, while others wrote the calculations on paper.

After a while, a child with dimples on his face raised his hand and said the answer: "Both the surplus and the deficit are twelve."

Liu Xueting looked at him and compared with the information he had seen before, it should be Sheng Lanting, the direct grandson of the Taifu family.

The current Golden Sun class has lost one Su Hanshan, and there are still seven children in the class.

Commander Yi, the royal princess.Xue Bo, the grandson of the eldest princess of Langhua.Zhang Wenxiu, the grandson of Youxiang Zhang.Mo Wuyou, the eldest son of the Minister of War.Sheng Lanting, the direct grandson of Taifu.Wang Lingxi, the youngest daughter of the Wang family, one of the top aristocratic families.Fu Heng, the second grandson of the Minister of Hubu.

In this battle, no other class has gathered so many powerful families.Dr. Zhou nodded appreciatively: "Since the calculation is twelve, then the calculations after the calculation are consistent are the correct values ​​of neither profit nor loss. Therefore, they can be combined as reality, and surplus and deficiency can be combined as the law."

"Qi is 32, which is four false decrees, with a surplus of twelve; Qi is 21, which is three false decrees, with a deficit of twelve; and seven false decrees are combined into one real decree, so three and four are combined into a law. In this way, you Do the math again?”

Children, you look at me and I look at you, all blinking with big confused eyes.

Dr. Zhou said "Hey" and called Xie Yu's name: "Assistant Professor Xie, tell me!"

"Yes." Xie Yu walked up to the teaching platform and pointed to the numerical value in the question, "One of the techniques is: combine surplus and insufficient to be real. The output rate is reduced from less to more, and the remainder is the law. Reality is as long as the law Get the number of people. If there is a surplus of three or less than four, the sum is seven, that is, the actual number is seven. The calculated rate is from less to more, less from seven, more from eight, less from more, which is one, that is, the law is one. The actual number is seven. , that is, the number of people. The number of people multiplied by the output rate, minus the surplus or supplementary deficiency, is the price. Therefore, the price is 53 qian."

"Do you understand?" Xie Yu Qingqian asked in the classroom.

Liu Xueting touched her chin and couldn't help but nodded secretly. After Xie Yu explained it, she understood!
In fact, it is similar to the modern method, but the wording is slightly different.For example, the actual refers to the dividend, the method is the divisor, and the actual method refers to dividing the dividend by the divisor. In this way, the number of people is obtained, and the price can be calculated by putting the number of people into it!

The same is true for Dr. Zhou's algorithm, which is only a little more convoluted than Xie Yu's.

Unexpectedly, Dr. Zhou asked Liu Xueting again: "Assistant Professor Liu, how did you calculate it? I think you just glanced at it that day and got the result very quickly."

!Can she say that it is a direct expression of the unknown?

No!

The time-traveling senior has not become popular, how dare she say that!

Then a smile appeared on her lips: "Hi, mine is almost the same as Assistant Professor Xie's."

Dr. Zhou just nodded and said no more.

The children buried their heads and wrote calculations on the manuscript paper.

After they all understood, Dr. Zhou asked another question.

"Now we are buying chickens together. Each person pays nine yuan, leaving a surplus of eleven yuan; each person pays six yuan, which is less than sixteen yuan. Question: How much are the number of people and the price of the chicken?"

"You can start calculating this question now. If you have done it, raise your hands."

After everyone had finished their calculations, Dr. Zhou asked Xue Bo to answer by name.

Xue Bo stood up confidently and said loudly: "A total of nine people bought chickens, and the price was [-] yuan."

Everyone clapped, which made Xue Bo touch his head in embarrassment and smile honestly.

After Xue Bo sat down, Dr. Zhou was still dissatisfied: "Although you have all calculated it, it was too slow. This shows that you are not proficient in memorizing the nine-nine table. I will not leave any homework today. In arithmetic class, I have to memorize the ninety-nine tables!"

Suddenly, the whole Jin Yang class was filled with wails.

"It's the ninety-nine watch again!"

"Can you not carry it?"

"Help……"

　Description:
　　Because it is an Imperial Academy kindergarten and the heroine is a teaching assistant, in addition to eating melon, there will also be some courses that children of this dynasty need to take.

　　The reason why arithmetic is described in detail is that the heroine will later popularize Arabic numerals, solve equations with unknown numbers, etc.

　　However, our ancient mathematics also has many achievements, such as the nine-nine table, the decimal system, etc. Therefore, the fictional Daxia Dynasty set in this article has a basis in arithmetic. Most of the topics cited in this article come from "Nine Chapters of Arithmetic".

　　
　
(End of this chapter)