Li Chunfeng was fascinated by the sight and couldn't help but pick up the white paper on the desk and read it carefully.

The various lines crisscrossing on the white paper vividly outline a three-dimensional figure, and even those who don’t understand how to read the picture can roughly see it.

Some ancient Indian (Indian) numbers marked on the edges of the lines, which obviously represent the lengths of each position.

Originally, some complex drawings allow you to see the measurements required for length, width and height at a glance, but there are some calculation formulas on the side that Li Chunfeng cannot understand.

Compared with the floor plan commonly used in the Tang Dynasty, this three-dimensional drawing and labeling method is both convenient and intuitive.

If it is used in large-scale projects or palace buildings, wouldn’t it make the supervisor clearer and follow the size step by step in an orderly manner?

In this way, there will be no repetitive work and no errors are prone to occur.

The more Li Chunfeng thought about it, the more interesting he felt, and his thinking gradually ran away.

Even though Li Chunfeng claimed to be a scholar and knowledgeable person, it was still a bit difficult to see these ancient Indian numbers.

Especially some formulas next to him have never seen them.

For example, there are some symbols of +-ⅷ÷ that make him confused.

Although it is a bit unclear, it seems to be too convenient.

After looking at it for a while, Li Chunfeng asked with a puzzled look: "Boy Zhongyi, this drawing looks clear at a glance and is very intuitive. What does it represent by the units marked with ancient Indian numbers and the symbols next to it?"

After looking at it, the drawings are easy to understand, but the numbers marked make him a little confused.

This is the drawing of the kang. If it is built according to the "division", it will be too small. If it is calculated according to the "in" it will be too large.

Only then did Yang Fan realize that the units of measurement in the Tang Dynasty at this time were different from those in later generations, and the annotations on paper were of course in centimeters because of habit.

Because there are five main units of measurement in the length of the Tang Dynasty, namely, cube, cube, zebe, and yin. There is no such unit of measurement as centimeters yet.

If converted, one inch is about 3.33 cm, which is no wonder Li Chunfeng is a little confused about the unit of measurement.

What surprised Yang Fan even more was that Li Chunfeng actually called Arabic numerals ancient Indian numerals, which made him a little difficult to understand.

But Yang Fan didn't know that Arabic numerals were actually invented by ancient Indians.

In ancient India, urban construction, sacrifices and other aspects required calculations of the operation of the sun, moon and stars, so mathematical calculations were produced.

Around three thousand BC, the numbers of residents in the Indus River Basin were relatively advanced, and the decimal calculation method was used.

A set of numbers from "1" to "0" tends to be perfected.

The ancient Indian numbers first spread to neighboring countries such as Sri Lanka, Myanmar, and Cambodia.

In the seventh to eighth centuries AD, the Arab Empire, which spanned Asia, Africa and Europe, rose.

While the Arab Empire expanded around, the Arabs also widely absorbed the advanced cultures of ancient Greece, Rome, India and other countries.

As time went by, by the 14th century, Chinese printing technology spread to Europe, which accelerated the promotion and application of Indian digital in Europe.

Westerners accepted the Indian numbers transmitted through Arabia, but they ignored the ancient Indians at that time and only considered them the achievements of the Arabs, so they called them Arabic numbers.

This wrong name has been passed down to later generations, so Yang Fan did not know the origin of Arabic numerals.

In fact, the real name of Arabic numerals during the Tang Dynasty was ancient Indian numerals, and their popularity was extremely low.

Yang Fan was still a little surprised that Li Chunfeng was able to understand Arabic numerals. This bull-nosed Taoist priest has a very good knowledge.

However, Yang Fan was also afraid of revealing himself in front of Li Chunfeng, so he accidentally cheated him, so of course, the unit of Xinmi is not easy to explain.

After all, this is a unit of measurement in later generations.

The calculation formulas next to it are all about calculating material products, so we can say it.

Looking at Li Chunfeng's eyes full of curiosity, Yang Fan couldn't bear to refuse, and he might have to ask this bull's nose for a while.

Thinking of this, Yang Fan explained: "Actually, this was learned from an old Taoist who traveled around the world when he was a child. However, he called these numbers Arabic numerals. These formulas are auxiliary calculations, and the length measurement units are also different. This is what..."

Li Chunfeng listened carefully, without doubting it.

In fact, Li Chunfeng didn't care what the number was called, nor did he care about what the unit of measurement was. What he was more interested in were the calculation formulas.

Although I can't understand it, I always feel very powerful.

"Is this why Bo Zhongyi could answer Xu Zhang's answer to the last time? Can you teach me?" Li Chunfeng pointed to the formulas of addition, subtraction, multiplication and division, and his eyes flashed with excitement.

Helplessly, Yang Fan had to bite the bullet and explain the simple algorithm of ten Arabic numerals and addition, subtraction, multiplication and division.

Li Chunfeng listened attentively for a long time, frowned and pondered for a while.

Finally, he shook his head and said, "This number is quite novel with such an algorithm, but that's all. It's not as clever as our algorithm. So how did you quickly calculate the problem of mixing carts with carts in Wangyue Tower?"

Of course, Yang Fan knew what Li Chunfeng was talking about.

When he was fighting with Xu Zhang, he heard Xu Zhang say that he also gave this question to Li Chunfeng for advice.

However, these calculations on paper are formulas of material product, and the binary equations involved were of course different.

Send Buddha to the West!

Yang Fan had no choice but to recite the multiplication formula to Li Chunfeng and explained the method of using binary equations.

As the saying goes, one way is to know all things, Li Chunfeng quickly figured it out.

As the Grand Historian, he was in charge of the revision of the calendar and was actually an astronomer and geographer.

Regardless of astronomy and geography, it needs to be combined with a large amount of data operations.

From ancient times to the present, any astronomical and geographer must be a master of science and calculation.

This is also why Li Chunfeng became a great person in the Tang Dynasty's art arithmetic world.

Although there was also a mathematics and mathematics subject in the imperial examinations in the Tang Dynasty, in the era when Confucian Neo-Confucianism was prevalent, disciplines such as mathematics, physics and chemistry were actually strange and erotic techniques and were left-handed.

There is no such saying in later generations that you are not afraid of learning mathematics, physics and chemistry well and traveling all over the world.

In this era, no matter how good you learn magic, you can only become an eighth or ninth rank official at most, so those who read are more keen on learning the Four Books and Five Classics.

In their opinion, learning the Four Books and Five Classics is the shortcut to getting promoted and wealth.

A master of calculating skills like Li Chunfeng can become a fifth-grade Taishi Ling. In addition to being extremely calculating skills, more importantly, he is a master in the Taoist sect, and his knowledge is not bad.

Hearing the methods and mantras taught by Yang Fan, Li Chunfeng buried his head in studying for a while, as if he was crazy.

He directly picked up the water core pen on the desk and wrote and painted in a distorted manner.

Li Chunfeng directly wrote two large sets of values, one in traditional Chinese and the other in Arabic numerals.

After comparison, I saw that traditional Chinese characters were too complicated and crossed out again.

Finally, in the group of Arabic numerals, the result is quickly calculated with multiplication formulas, and then two values ​​are divided, and the result is quickly obtained by listing the formula. I was surprised.

With a scream, Li Chunfeng stood up solemnly and said in admiration: "This number is simple to write. I didn't think it was at first, but the more complex it involves, the easier it is to calculate it. This number is combined with such formulas and formulas, which is simply a genius idea. From then on, I can save much worry when calculating astronomy and other calendars. Thank you for your teaching. It's really better to listen to your words, it's better to read ten years!"

Although she was so fluttered by Li Chunfeng's high hat, Yang Fan clearly realized that he was just standing on the shoulders of the giant civilization that had been for thousands of years.

So he waved his hand awkwardly: "This is all taught by the Taoist priest Yunyou when he was a child..."

Although Yang Fan said this, Li Chunfeng did not believe it. In his opinion, if this method had been invented before, it would have been popular in the world long ago.

However, Li Chunfeng did not delve into it, but instead seemed more respectful, and only then did he remember another purpose of coming here.
Chapter completed!