Zheng Liuyi and a few people, under the leadership of the housekeeper Yun Song, crossed Chong'an Street along Yong'an Street, crossed Yanshoufang, and came to the vicinity of Kanglufang in a quarter of an hour.

Originally, Kanglu Fang is very close to the Golden Mile Square where Yunfu is located, located directly opposite the West Market, and the house along the street is a very magnificent restaurant, and the three big characters of "Cyclamen" written on the door are very vigorous and powerful.

It's just that the building is a little dilapidated and not glamorous enough, presumably because the owner has no intention of operating and is too lazy to take care of it.

Along the way, Yun Songwu chattered and introduced Zheng Liuyi to the situation of the shopkeeper.

The shopkeeper's surname is Zhen, and he is obsessed with arithmetic, and recently it seems that he has been newly granted a county order in Hanzhong County, and he is about to go to work.

His father was a royal historian of the Sinong Mansion, although his official position was not very prominent, but he held real power in his hands, and he handled countless amounts of money and food in a year. The shopkeeper surnamed Zhen likes arithmetic, and nine times out of ten he has been nurtured by his family.

Zheng Liuyi and everyone walked into the restaurant, only to see that the hall on the first floor was very spacious, with windows open on all sides, and a thin light veil was pulled in front of the window, making the hall appear very bright and seemed to be integrated with the prosperity of the street outside.

But the curtain is separated, but the hall shows a bit of quietness, a bit of quiet taste. It is very rare to have this kind of design in this era.

Zheng Liuyi couldn't help but nod his head again and again, and as far as his eyes could see, he saw a scholar standing at the counter, less than thirty years old. The scholar frowned, and was engrossed in fiddling with his calculations.

After fiddling for a while, the scholar suddenly raised his hand to put the calculation chips together, looked up and thought for a moment, then grabbed the calculation chips again, and fiddled with them seriously in the wooden plate, as if he was ignoring Zheng Liuyi and the others.

Yun Song led Zheng Liuyi and the others to the counter, and said to Zheng Liu: "Zheng Gongzi, this is the shopkeeper Zhen Gongzi, if you want to buy the shop and real estate here, Zhen Gongzi can call the shots." ”

Zheng Liuyi arched his hand to the shopkeeper and said: "Under the surname Zheng, dare to ask Zhen Gongzi how much silver does this restaurant and the house behind it cost?" ”

The shopkeeper stopped what he was doing, raised his eyes and glanced at Zheng Liuyi, not like a rich man, so he said casually: "It turned out to be Zheng Gongzi." The price of my store is 4,000 taels, and the house behind it has two parts, one is a property purchased by my father, and the price is 2,000 taels; One is entrusted by Lord Wang of Zhishi for sale, and the price is 4,000 taels. ”

Zheng Liuyi pretended to look at the room and asked, "I see that this place is in a good location, I don't know why the shopkeeper wants to make a move?" ”

"My father is going to work this month, and he is about to take up his post in the future, and there is no one to take care of it here, so it is better to sell it and save worry. If Zheng Gongzi wants to buy it, the price is 10,000 taels of silver. If you don't like it, look elsewhere. ”

After the shopkeeper finished speaking, he grabbed the calculation chip again and lowered his head to fiddle.

Although the tone is quite polite, it always sounds a bit of a customer. If you want to bargain, it seems that there is no way.

Yun Song's face was slightly embarrassed, he looked at Zheng Liuyi, frequently glanced at him, and signaled to leave.

Xiao Chenyan said directly: "Zheng Gongzi, there are many shops in Kyoto, why don't we take a look elsewhere?" ”

After speaking, he carefully observed the changes in the shopkeeper's expression, but the shopkeeper didn't even raise his eyelids. Xiao Chenyan had no choice but to spread his hands to Zheng Liuyi, implying that this trick was useless.

"No hurry, no hurry." Zheng Liuyi smiled at Yun Song and the others, and then turned his eyes to the shopkeeper's wooden plate, only to see that the calculation chips were placed horizontally and vertically, and he couldn't understand it.

On a piece of paper next to it, it was written in block letters: "I don't know how many things are, three are more than two, five are more than three, seven are one and two are left, and ask what is the total number of things?"

This topic is a famous "things do not know the number" problem in the history of Chinese mathematics, which belongs to a congruence problem, as a science and engineering man, Zheng Liuyi has done special research, so he said casually: "This is not difficult to calculate, twenty-three only." ”

Shopkeeper Zhen glanced up at Zheng Liuyi rarely, and then said disdainfully: "It's just a number, it's not a good thing." ”

Indeed, the numbers given in this problem are simple, and as long as you make up a few numbers, you can solve it quickly. Unexpectedly, this shopkeeper is looking for a unified solution, and it seems that he is a person who pursues arithmetic.

Unexpectedly, he was disgusted, Zheng Liuyi couldn't help but feel funny, and secretly pondered to himself, and told him the remaining theorem, I guess he didn't understand it, right?

So he laughed and said: "The three of them are seventy thin, five plum blossoms are twenty-one branches, and the seven sons are reunited for half a month, except for one hundred and five." "

The shopkeeper was stunned when he heard this, and then his eyes were empty, and he muttered in his mouth: "The reunion of the seven sons is half a month, and I will know it except for one hundred and five." Divide one hundred and five and you will know..."

Then he grabbed a handful of calculation chips and quickly put them on a wooden plate, and said something in his mouth: "Count three or three, take the number seventy, and multiply it with the remaining two; If you count five or five, take the number twenty-one and multiply it with the remainder three; For the number of seven-seven, take the number fifteen and multiply it with the remainder two. Then subtract multiples of one hundred and five. ”

Swinging and swinging, this Zhen shopkeeper suddenly jumped up, danced with his hands, and shouted: "It's solved!" Wonderful, wonderful! ”

This time he jumped and screamed, completely lacking the elegant and indifferent temperament he had before, but it scared Wushuang, Yun Xuening and others.

Yun Xuening glanced at the shopkeeper strangely, then turned her gaze to Zheng Liuyi and said, "Zheng Gongzi, I didn't expect you to be proficient in arithmetic!" ”

Wushuang was already surprised by this, and looked at Zheng Liuyi with a smile on his face, with a little pride in his heart.

After jumping a few times, the shopkeeper walked out of the counter, came to Zheng Liuyi, bowed and saluted: "In Xia Zhen Luan, dare to ask Brother Taizun's name?" ”

Zheng Liuyi replied: "How dare you, junior brother Zheng Yuanyi." ”

There are many strange people in this world, some people are obsessed with martial arts and are called martial arts idiots; Some people are obsessed with the pleasure of two loves, and they are called infatuated; This person is obsessed with arithmetic, and he should be called an idiot.

Thinking of this, Zheng Liuyi smiled slightly, since you are good, I have a way to get close to you. So he said: "Brother Zhen, junior brother has another question here, I wonder if Brother Zhen can answer it?" ”

The real murderer? Zheng Liuyi always felt that this title was a little awkward.

Zhen Luan immediately became interested when he heard this, pulled Zheng Liuyi to the counter, enthusiastically took out a pen and paper, handed it to Zheng Liuyi, and said, "Brother Zheng, please ask the question!" ”

"Brother Zheng" doesn't seem to be much better than "Brother Zhen", Zheng Liuyi was speechless for a while, took a pen and paper, brushed and wrote a line of small characters on the paper: There are pheasants and rabbits in the same cage today, with thirty-five heads on one and ninety-four feet below.

This is the famous problem of chickens and rabbits in the same cage recorded in the ten books of the Book of Calculations, which has stumped countless primary school students, I don't know if this problem has appeared in this era, and used it to test him.

Zhen Luan read the question several times, scratched his ears and cheeks, and said: "Wonderful, there is such a subtle arithmetic problem in this world, which is really unseen and unheard of." ”

Then he turned his gaze to Zheng Liuyi: "Brother Zheng, you must have already solved this problem, right?" ”

"Exactly!" Zheng Liuyi nodded slightly.

"Then why don't you explain it to the little brother?" Zhen Luan's face was full of eagerness, at this time he had changed from indifference to very enthusiastic, and even called himself a junior brother to Zheng Liuyi, who was more than ten years younger.

Zheng Liuyi smiled and said: "Brother Zhen is not in a hurry, let's talk about the house price first, and then talk about the problem?" ”