"A country of thousands of chariots has an area of ​​thousands of squares and a total area of ​​nine billion steps. How many square meters does it have?"

This is an example question from "Nine Chapters of Arithmetic". It only involves simple unit conversion and the square root of billions of digits. Naturally, it is not a problem for Xuan. He answers easily, "Three hundred and sixteen miles and sixty-eight steps. Directly.

It can be obtained by calculating the square root.”

"There is a sacred tree in Kongsang. It grows one foot in the first year, half a foot in the next year, and half a foot in each year. Question, after a thousand years, how tall will it be?"

Xunzhi responded casually without thinking, "Two feet."

Qingyun stuck out his tongue and continued to ask, "Today there is a round barn, six feet next week, seven feet last week, and six feet high. We are entrusted with new rice and the tip is one foot high. I want to ask, how much does the meter cover?"

After hearing this question, Xun Zhi suddenly looked solemn, turned to Chen Wenzan and asked, "Did your father really tell Brother Chen that he must solve these questions before he can leave home?"

Chen Wenzan nodded, "My father specifically told me that it must be approved by my husband. Otherwise, my husband will be required to supervise the school and we cannot travel far."

Xunzhi sighed, glanced at the three people, and finally stopped at Hu Caiting.

I saw the latter smiling like a flower and looking innocent, not like he could hide his worries at all.

I hope I am worrying too much. I muttered to myself in my heart, "I can't solve this problem. Brother Wenzan needs to ask my father for more advice. I am also powerless about today's matter. Brother Wenzan is afraid of the trip north."

It’s going to be a miss.”

Calculating the volumes of cones and cylinders was originally a difficult task.

But looking at the world, we can calculate arithmetic and find that those who are good at grains of rice can only count on ten fingers. I am afraid that half of them have fallen into the ancestral family.

Chen Daoju was afraid that for some inconvenient reasons, he knew that he could not stop Qingyun this time, but wanted to keep his son Wenzan at home.

Zu Xunzhi often went out with his father for surveying and mapping, and his master collected herbs and made elixirs. He was often out and about. Unlike Qingyun, he was still a young boy who didn't know the world.

He secretly thought that the incident in Tan Palace was, in the final analysis, an internal fight within the sect.

Therefore, it is difficult to predict whether the trip to Wei will be good or bad, and the Hu Caiting whose master is unknown cannot be fully trusted.

Perhaps Uncle Chen and his father had already noticed today's situation. When Uncle Chen left the sutra calculation, he had already guessed that Qingyun would come to find him, and his father "happened" to plan a trip to the Northern Wei Dynasty for him.

It's a kind of entrustment.

After thinking about this, an apologetic smile appeared on Xuan Zhi's face, as if he was still worried about something that could not be solved.

Unexpectedly, Chen Wenzan was very free and easy, "Hey, I don't know how to swordsmanship, so it's a burden for you to carry me with you. I'd better ask my ancestors for advice and make up my mind first. My father also hopes that I can use this to gain fame in the future.

, to make a living."

Hucaiting pouted and slapped Chen Wenzan hard on the head, "Your brain needs to be replenished! Read more and maybe you can become an emperor!"

Chen Wenzan shook his head and choked angrily, "Tsk, the teacher who taught me last time gave me a fortune telling. He said that my fortune coincides with the Nine-Five Lord, and I will be blessed with endless blessings. I should not be too far away from the Dragon Throne.

.Mr. Huayang’s hexagrams are always very accurate, brother Xuan, don’t you think so?”

Zu Xinzhi was helpless at his optimistic nature. He spread his hands and slightly raised the corners of his mouth in a joking manner, "I hope it's accurate this time! Master also said that I can marry a princess. To be honest, apart from numerology,

I obey everything sir."

Caiting rubbed Qingyun's arm with his shoulder and asked mysteriously, "Has Mr. Huayang ever told your fortune?"

Qingyun shook his head slightly, "Uncle Chen said that Yi Xue is the way to live in the world, not a way to seek good luck and avoid evil, so..."

Chen Wenzan snorted coldly, "Bringing my dad out again. My dad also said that Mr. Huayang is not an ordinary person. Hearing one word from him is better than ten years of reading."

Then he squeezed his eyes and said to Caiting, "He is afraid that his fortune will be too weird and scare you. Mr. Huayang said that Brother Qing has the form of 'nine dragons surrounding the pillar'. He is that pillar and the pillar of the world."

, he will meet many noble people with the real dragon zodiac sign walking around him in his life. Hey, I will be the first one. Haha~"

Being bound by the destiny of a true dragon, meeting one would be a blessing for an ordinary person.

Nine dragons around the pillars? What kind of monster is this guy?

Hu Caiting secretly murmured in his heart, whatever, the current situation in Luojing is like a tiger and a dragon, and there is an undercurrent surging. Maybe this fledgling boy is the destiny to break the situation?

What about your own fate? What about the fate of your tribe?

Huh? Nine dragons surround the pillars. Even if we include the emperors of the Northern and Southern Dynasties, it is still far from enough. Could it be that outside of China, the future emperors from all over the world will be intertwined with his destiny? Then...

"Hey, what are you thinking about? Are you really scared?"

Looking at the surprised looks cast by the three of them, Hu Caiting knew that he had lost his temper just now, so he forced himself to say perfunctorily, "I think I'm a little tired. I've been running all day without a break. I have to go on the road tomorrow."

Xunzhi smiled knowingly and placed Hucaiting in the bedroom behind the courtyard to rest.

This Star Observation Pavilion is not a place for guests to receive guests. There are no guest rooms, so the three grown men can only make do with each other in the pavilion for one night.

Early the next morning, Hu Cai Pavilion was awakened by a rapid golden sound. In the haziness, he could see that the indoor light was shining brightly, with seven colors. Several light beams focused on a metal pillar on the inside of the gable wall, reflecting a blazing white light.

Can't look straight.

Caiting was shocked and surprised, and suddenly woke up, and those few light pillars suddenly disappeared, replaced by the soft natural halo of the morning sun.

The three people in the pavilion chatted a lot last night and were still dreaming, but Hu Caiting rushed in shouting as if he had been given blood.

The three of them reluctantly rubbed their sleepy eyes with wry smiles on their faces.

Xianzhi yawned and said, "Well, I said she would come early in the morning to wake us up so that you could go to bed early last night."

Qingyun laughed, "She looks much more nervous than when I first saw those damn things of yours."

"Are you just kidding me and not reminding me to be wary of those weird mechanisms?" Hu Caiting looked sulky, with two eyebrows raised, just like a pair of scimitars, as if they would be chopped off if they disagreed with each other.

Clearly irritated.

Yuzhi waved his hand, "I don't dare to laugh at girls, but if I warn you in advance, there won't be that sense of mystery, and it will be a lot of fun. It's just a small mechanism to urge me to get up and dance swordsmanship when the weather is nice.

To put it bluntly, it’s not worth a penny.”

Hu Caiting knew that the other party did not have any malicious intent, and as his curiosity surged, his anger was diluted, "How was it done? Those light curtains are... quite beautiful. The sun is rising at this time, can it be automatic?

Sensing the sun?”

"So be it.

When making the dome mirror, my father and I took some scraps and ground them into an eight-sided condenser mirror and hung it under the eaves of the east window.

If it is a sunny day and the sun rises, these mirrors will focus the sunlight on the lead rods on the gable wall.

There are actually two lead rods, and the other one is in the machine room next door.

The two lead rods are basically the same height, holding a wooden trough open at one end, and the trough is filled with copper beads.

Normally, this wooden trough is slightly tilted toward the closed end, so the copper balls cannot roll out.

But concentrated light can generate heat, and the lead rod will stretch a little when exposed to heat.

In this way, when the sunlight shines in, it will raise the closed end of the wooden trough, and the copper beads will roll down from the opening on the other side, hitting the copper plate below and making a sound.

When all the copper beads fall into the copper plate, the mechanism will be pressed to retract the condenser, the heating will stop, and the temperatures of the two lead rods will gradually return to equilibrium.

And every night at midnight, when the large ejector releases the water and resets, the mechanism will be triggered to lower the condenser, and the wooden trough will be filled with recycled copper beads, waiting for the next sunrise."

Concentrating light generates heat, and lead expands with heat. These principles are really unfamiliar to Hucaiting.

Although she only heard about it in a vague way, she also believed that the mystery in this pavilion was like a magical craftsmanship, and she could only be in awe. "I, let's leave this ghost place as soon as possible. Every step here is full of traps. It's the wrong way to go."

One step is a shock. The lights in the corridor will extinguish themselves, the incense will burn itself, the tea will cook itself, and even the toilet will clean itself..."

"These are not difficult. In fact, we just need to find the right actions that we are used to triggering, such as opening and closing doors, sitting, standing, walking and stopping..."

"Stop! I just want to leave now." So she left and ran out without looking back.

"You go ahead, I'll help you look at the Star Gazing Pavilion." Chen Wenzan waved his hands to the two of them, as if he had made a very happy decision.

"That's good enough." There was a junior student who helped record the star map, and Xuan Zhi naturally wanted it, so he finally put aside his last worry and said goodbye together with Qingyun.

It is said that the three young people were walking together, so they couldn't stop talking.

Especially Qingyun, who had just learned about his life experience, kept asking endless questions about the situation of his sect and the general trend of the world. Caiting and Xunzhi also relied on their knowledge and took the trouble to explain.

Regarding the Five Sword Sects in the World, this has been said since ancient times.

According to legend, the five emperors used force to establish the country, and each passed down his secrets.

Yellow Emperor Xuanyuan Sword,

The male and female swords of the Red Emperor,

Qing Emperor's Star-relegated Sword,

Black Emperor Xuanwu Sword,

White Emperor's Ape Sword,

And they are the five ancient sects.

The Xuanyuan Sword of the Yellow Emperor was lost for a time. When the Chu and Han Dynasties were fighting for hegemony, King Xiang obtained the fragments of the sword and became proud of it with the Overlord Sword.

Sun Jian of the Three Kingdoms also studied the remaining chapters of Bawang. When his descendants Sun Ce and Sun Yi died, the essence of the Xuanyuan Sword was lost.

Ma Mengqi from Xiliang Majia's family was named one of the Five Sword Sects, the Western Sect, because of his domineering and fierce skills and his spiritual resemblance to Xuanyuan.

However, since Ma Chao's death, few practitioners of this method have achieved great success, and it has gradually declined among the five sects.

The Red Emperor Sword was passed down to the Liu family. From the time Liu Bang established his power by killing snakes to the time Liu Xianzhu Gu Yingfa took shape, during the five hundred years of the Han Dynasty, this sect became a national martial art and its reputation grew, becoming the first of the five sects.

Liu Song, the former Southern Dynasty, embraced his skills. After the fall of the Song Dynasty, the ninth prince Liu Chang fled north to Wei and was named King of the Song Dynasty.
To be continued...