Meng Qingqing can go, but of course Yang Xuan can't.

After Chuanyin persuaded Meng Qingqing and told her not to tell her about herself, Meng Qingqing reluctantly left with Ling Wudao.

However, Yang Xuan was very skeptical that she was reluctant to give up on herself or snacks.

After Meng Qingqing left, Xie Tianji continued: "Brother Ren, let's explain the shadow measurement method." ”

At this point, Yang Xuan didn't want to hide it, so he explained some similar shapes and proportions to Xie Tianji in detail, and this explanation was even more detailed and further than the previous explanation for Zhang Heng.

Xie Tianji obviously understood, and after pondering for a while, he sighed and said: "I heard about the method of shadow measurement before, and I thought it was a small way, but now I listen to Brother Ren's explanation, and I know that this is also a great way, and Brother Ren's attainments in mathematics are really extraordinary." ”

Then he said, "But you don't know how to measure the Zhou Zhizhi?"

Yang Xuan looked at Xie Tianji and said, "Old Xie, do you know what the Qingxue Imperial Family used to test Zhou Dezhifa?"

Xie Tianji was slightly stunned, then his gaze fell on Yang Xuan's fingers, and he smiled: "If Brother Ren still wants a storage ring, then my Biyun Sect doesn't have it." ”

Yang Xuan didn't wonder why he knew such a secret, shook his head and said, "Old Xie said with a smile, it's useless to have more storage rings, I only need one thing." ”

Xie Tianji's eyes narrowed, and he said, "What?"

Yang Xuan went straight to the point: "Your Elder Sect Keqing Token." ”

Xie Tianji was stunned for a moment, he was ready to listen to Yang Xuan's lion speak, but he didn't expect Yang Xuan to make such a request.

To tell the truth, Yang Xuan's request is nothing at all, but it is good for his Biyun Sect, just think about it, a Five Qi Great Venerable, no matter which sect he goes to, he can be treated with dignity, it is simply something that cannot be asked, but Yang Xuan put it forward as a condition.

"What's so difficult about this, if Brother Ren wants to join my Biyun Sect, it's exactly what I can't ask for. Xie Tianji patted his chest and said.

Yang Xuan sighed, his move was also a last resort, if he didn't want this Keqing token, whether Ling Wudao could let him leave was still unknown, you know, he still had to dig spirit stones, and he definitely couldn't stay in Biyun Sect.

Xie Tianji called a person, and after arranging a few words, the person turned around and left.

After a while, Ling Wudao walked in, handed a cyan token to Yang Xuan, and said with a smile: "Elder Ren, welcome to join my Biyun Sect." ”

Yang Xuan smiled, put the token away, and didn't speak.

Ling Wudao continued to laugh and said, "Elder Ren, this token you hold is the highest status of Elder Keqing Token, and it has many rights, which shows the sincerity of my Biyun Sect, and I hope that Elder Ren will not disappoint my Biyun Sect." ”

This was already a warning, how could Yang Xuan not hear it, he nodded to Ling Wudao and didn't say anything.

The whirlpool between the Biyun Sect and the Giant Spirit Sect, he didn't want to fall into it, he just wanted to dig out the spirit stone and fly away.

With this Biyun Sect's token, it would be much easier for him to act.

Of course, he knew that Biyun Sect could accept his request because of his knowledge of mathematics and Xie Tianji's face, and secretly launched an investigation against him, and even when his identity would be revealed, which was why he wanted the identity of a guest elder.

Xie Tianji was already waiting impatiently on the side, and said, "Brother Ren, now I can talk about this method of measuring Zhou Dezhi." ”

Hearing this, Ling Wudao also showed a deferential expression.

Yang Xuan didn't be verbose, he opened his mouth directly, and explained the relevant knowledge of pi to the two of them, of course, he kept an eye on it, and did not explain it too carefully, and even pi, he was only accurate to two decimal places, the same as what he told the Qingxue royal family.

He had a hunch that it was very likely that the hand he left behind would bring him unexpected gains.

Xie Tianji couldn't wait to check it on the ground, and Yang Xuan found that the bluestone ground had already been covered with all kinds of messy graffiti, and it seemed that Xie Tianji usually had the problem of squatting on the ground to check the calculation.

Ling Wudao looked at Yang Xuan with a sigh, although he was not as professional as Xie Tianji in mathematics, he also understood Yang Xuan's explanation.

For Yang Xuan, he couldn't help but really admire it in his heart at this moment.

Xie Tianji checked the calculation for a long time, suddenly slapped his thigh and stood up, suddenly rushed to Yang Xuan, grabbed his hand and said excitedly: "How did you find this? Genius, simply genius." ”

Yang Xuanxin said: The elementary school math teacher taught me.

But of course he couldn't really say that, just a smile and pretending to be mysterious.

A few days later, when Yang Xuan was about to leave the Biyun Sect, Xie Tianji sent Yang Xuan to perform a disciple salute.

From the disdain at the beginning, to the respect for heaven at the end, in just a few days, Yang Xuan's display of the tip of the iceberg in mathematics made Xie Tianji and Ling Wudao a little numb in shock.

Especially Xie Tianji, he boasted that he was a scholar of heaven and man in mathematics, and no one in the world could match him, but compared with Yang Xuan, it became a joke.

Any question he raised, when it came to Yang Xuan's hands, could always be answered in the fastest and most correct way, and it seemed that there was no problem in the world that could stump him.

In the end, Xie Tianji simply couldn't understand what Yang Xuan was saying.

What Aix, what Aunt Wa, what Eagle, but Eagle, all of them were confused and happy.

He sometimes thinks that Yang Xuan is talking nonsense, but any question, Yang Xuan can always answer it in these bird languages that he doesn't understand, and he can't help but believe it.

Even, he once heard a sentence coming out of Yang Xuan's mouth: The chicken becomes the same lotus, and the charm ......

At that time, Yang Xuan was only halfway through the words and then stopped, Xie Tianji keenly felt that Yang Xuan's words seemed to contain some big secrets.

What is the relationship between chickens and lotus roots?

The middle-aged man who said that Yang Xuan couldn't afford to pay that day had already thrown himself to the ground for the five bodies that Yang Xuan admired, so he almost knelt on the ground and shouted master.

The reason is that once Yang Xuan accidentally saw him doing an experiment, so he casually pointed out a few words, and solved a big problem of Xie Tianji, which made this disciple directly shocked, and never dared to make a mistake in front of Yang Xuan again.

Ling Wudao only listened to it for half a day before retreating in defeat, because after only half a day's effort, he couldn't understand what Yang Xuan said.

Before leaving, he was always thinking about one question: what exactly is factoring prime factors?

He had a hunch that if he could figure out this sentence, he would definitely make a qualitative leap in mathematics.

When Yang Xuan left, Xie Tianji and Ling Wudao were directly sent to the outside of the Biyun Sect, and the other disciples of the Biyun Sect who saw it were stunned for a moment, inexplicably in awe of Yang Xuan, and at the same time kept Yang Xuan's appearance firmly in their hearts, and listed it as an object that must not be offended.

What can make the two giants of the Biyun Sect send it together, how can they offend.

"Brother Ren, you must go early and come back early!"

In Xie Tianji's reluctant eyes like looking at his wife, Yang Xuan responded, and then quickly slipped away, and at the same time, he secretly wiped the cold sweat on his head.

If he goes on, he doesn't know what to say.

It's not that he can't, but no matter how advanced things are, they can't be understood in the language of this world.

In the end, he simply told Xie Tianji some concepts of unknowns.

At most, it's the second year of junior high school.

Yang Xuan secretly thought that at this time, he knew that it was not easy to be a teacher, and sometimes, looking at Xie Tianji's incomprehensible appearance, he couldn't wait to slap him twice.

Shaking his head, Yang Xuan threw out the strange thought of hating iron but not steel, and flew over in the direction of Qingxue City.

The thief is still there waiting for him to continue the great cause of digging the ancestral grave.

。 m.