Li Su came to Zhao Fu's mansion, and the steward immediately invited him to the living room, and in less than half an hour, there was a rush of footsteps outside the living room, and listening to the voice, there was more than one coming. Li Su thought that Yifan had come with his father, so he didn't care.

Zhao Fu came in and saw Li Su, and immediately stepped forward and saluted: "Your Highness!" ”

"Don't be polite!" Li Su smiled and helped the other party up, but his eyes looked behind him, but what he didn't expect was that Zhao Fu was not followed by Yifan, but two Taoist priests in Taoist robes, although these two people are different in age, they both look like fairies, especially the younger one, who is more than one meter eight tall, plus a handsome and mature face. It can be said that whether it is appearance or figure, he is a top male model, and Li Su is a little jealous when he sees it.

"Your Highness, let me introduce you, the older one is the famous Yuan Tiangang, Yuan Old Immortal! And this is the disciple of Yuan Lao Immortal, Taishi Ling Li Chunfeng Li! Zhao Fu saw that Li Su noticed the two of them, and hurriedly introduced them on his behalf. Originally, Yuan Tiangang's master and apprentice had long wanted to see Li Su, but because he didn't find a chance some time ago, it was delayed until today.

Although Li Su was surprised when he heard that the other party was Yuan Tiangang and Li Chunfeng, he had already learned from Zhao Fu that Yifan's master was Yuan Tiangang, so he also had a little guess in his heart just now, so he didn't show any special surprise.

"Poor Dao, meet Your Highness!" Yuan Tiangang and Li Chunfeng saluted together, although Li Chunfeng was an official, he also claimed to be poor. Obviously, he visited Li Su as an outsider.

"Hehe, the two immortal elders don't have to be polite!" After a moment of surprise, Li Su suddenly showed a smiling smile, and supported the two of them with a kind face, he was about to hand over something to Yifan to do, and he was afraid of delaying the development of the steam engine, but he didn't expect God to send these two magic sticks to him. Looks like I'm really lucky!

"I have heard for a long time that His Royal Highness has a handsome and extraordinary demeanor, and when I saw it today, it was indeed a dragon and phoenix among people!" Yuan Tiangang just got together. Immediately a smiling fart slapped over.

According to unwritten etiquette, Li Su should be humble at this time, but he smiled. He accepted the other party's compliment without blushing, and then said: "This king has also heard for a long time that Yuan Dao's appearance is unparalleled, but unfortunately he has never had the opportunity to meet, I didn't expect to meet in Zhao Beijia's mansion today, I don't know if I can also meet Li Suxiang, see how this king's fate is?" "Li Yu is still very curious about Yuan Tiangang's physiognomy, and wants to see if it is really as magical as the legend.

In fact, when he first met Li Su, Yuan Tiangang was already secretly observing Li Su's face, but what he didn't expect was that. On the surface, Li Su is just a rich but mediocre life, this kind of face is not strange compared to a prince, but if you carefully observe Li Su's inner essence, qi, and god three treasures. But it is full of unspeakable preciousness, and even he saw something from Li Su that should not have appeared.

After a long while, Yuan Tiangang suddenly showed a wry smile on his face and said: "Your Royal Highness, your face is the appearance of heaven and man, I am afraid that it is really as the world says, you are a heavenly immortal." Poor Dao is just a mortal, so naturally he can't see the fate of His Highness clearly. ”

As soon as Yuan Tiangang's words came out, not only Li Su was surprised, but even Zhao Fu and Li Chunfeng also showed incredible expressions, they were all convinced of Yuan Tiangang's physiognomy, but they didn't expect that there were faces in this world that he couldn't see. In fact, Yuan Tiangang also saw something, but he didn't dare to say it, so he could only use these words as excuses.

"Hahaha~, the Taoist is really good at laughing, I'm just a poor and lustful mortal, where can I be a fairy?" When Li Su heard the other party's words, he laughed and said, he liked this compliment, but he had a little disdain for Yuan Tiangang's physiognomy in his heart.

"Hey, by the way, why isn't Yifan here?" Li Su no longer paid attention to Yuan Tiangang's master and apprentice, but turned to Zhao Fu and asked, Zhao Fu is very doting on his daughter, and usually has almost no control over Yifan, and Yifan is usually like a boy, quite like those tomboys in later generations, and because of the steam engine, Yifan is also very welcome to Li Su, almost every time Li Su comes, he will see her greet him in person.

"Your Royal Highness, because of the setback in the development of the steam engine, Yifan has nothing to do now, and Yuan Lao Immortal is also here, so he started his studies again, and now he is studying in the back hall." Zhao replied. Yuan Tiangang next to him also stroked his beard and smiled, speaking of this little disciple, he was also very satisfied, not to mention his intelligence, the key was to work very hard.

"Oh, Yuan Daochang is a scholar of heaven and earth, and the disciples he taught are also extraordinary, and this king is also very curious, I want to see what kind of knowledge Yifan has learned, I don't know if I can let this king take a look?" Li Su asked curiously. In ancient times, when a master imparted knowledge to his disciples, outsiders were forbidden to watch it unless they had the permission of the other party.

"Hehe, if Your Highness is interested, Poor Dao is naturally honored!" Yuan Tiangang was the first time he met someone who made him unable to see his fate, so he was also very curious about Li Su, and he wished to know more about Li Su, so he readily agreed.

Even Yuan Tiangang agreed, and Zhao Fu had no reason to object, after all, Li Yu and Yifan were also acquainted, as for the defense of men and women, in the eyes of his doting daughter's father, he would have been thrown aside, otherwise he would not have allowed his daughter to go out casually, and she would do whatever she wanted.

Li Su followed the three of them to the back hall, and sure enough, he saw Yifan crawling on the bookcase, engrossed in writing something on the paper. The four of them didn't make a sound to disturb, and Li Su walked to Yifan's back gently, looked down, and found that Yifan's left hand side was a large piece of paper, the words on the paper he knew, and it looked like it should be an ancient arithmetic problem, Yifan was performing on the scratch paper next to him.

Li Su looked at the questions on the big paper, he is also the product of the all-round development education of later generations, mathematics is one of the compulsory subjects, so there is some foundation. But when he saw the problems on the paper, he was dumbfounded, they were full of words, without the familiar mathematical symbols of later generations, and there were so many technical terms on these topics that they were like a spy's code book.

Li Su watched it for a long time, and finally even guessed that Meng probably understood one, this problem is a simple binary equation problem according to later generations, as long as two equations can be listed, the result can be obtained, and even Li Su's mental arithmetic can get the result. Look at the pile of astronomical things written by Yifan again, they are almost full of paper, but they haven't come out yet.

Seeing this, Li Su couldn't help but shake his head, although he knew that the arithmetic of the ancient Chinese was very developed, but without the basis of mathematical symbols, it would be so troublesome to make a simple problem, let alone those more advanced topics.

Seeing Li Su shaking his head, Yuan Tiangang and Li Chunfeng were a little strange, stepped forward to look at the question made by Yifan, and found that there was no mistake, and at this time, Yifan also just calculated the answer, and the result was no problem, now they couldn't figure it out, Yuan Tiangang took the lead and asked, "Why did Your Highness shake your head?" ”

Before Li Su could answer, Yifan heard someone talking above his head, and looked up suspiciously, only to find that there were a few people standing behind him, and jumped up with a frightened 'ah', and when he saw that it was Li Su and Yuan Tiangang and others, he calmed himself down, and said with a dissatisfied face: "You guys are really, why did you run behind me and didn't remind me, you scared me to death!" ”

"Haha, we are watching you do the questions seriously, and we are afraid that you will be disturbed by your voice!" Li Su said with a smile, Yifan is not only extremely smart, but also very bold, otherwise he would not sneak away to the shipyard alone to see the ship model, usually when he sees himself as the king of Qi, he is also like treating an ordinary friend, he should fight and make trouble, without taking into account Li Su's identity, which makes Li Su find a feeling among friends in the future, but today he suddenly found that Yifan also had a timid time.

"Hmph, count your acquaintances, I just solved a nine-chapter arithmetic problem!" Yifan said proudly, and picked up the questions he did and handed them to Yuan Tiangang, and said coquettishly with a rare little daughter attitude: "Master, I have made all the questions you and my senior brother have made, have I passed my arithmetic?" ”

Li Su looked at her proud little appearance, smiled again and shook his head, Yuan Tiangang was entangled by a fan and couldn't get out of his body and asked Li Su, but Li Chunfeng was very idle, stepped forward and asked: "Why did Your Highness shake your head twice, is there something wrong with this algorithm?" ”

Li Chunfeng is most proud of his arithmetic, most of these questions are from him, and in his opinion, Yifan's work is also very standard, even if it is him, it will not be much stronger than Yifan.

"Hehe, there is no mistake, it's just that I saw that Yifan was too troublesome, so I shook my head twice." Li Su said with a smile, if the future generations take the mathematics test according to Yifan's approach, and the amount of questions is the same, it is estimated that the exam time should be extended to a whole day.

"Oh, Your Highness says so, so is there any simplification?" Li Chunfeng frowned after hearing this, although he knew that Li Su was very talented, but in terms of arithmetic, he had always thought that he was the first person in the Tang Dynasty, even if it was his master Yuan Tiangang, his attainments in arithmetic were not as good as him, so he still didn't believe Li Su's words.

Looking at Li Chunfeng's expression of disbelief, Li Chunfeng blinked his eyes, and suddenly thought of a good idea, so he smiled and said, "Daochang Li, how about we make a bet?" ”

"Oh, what's the bet?" Li Chunfeng asked lightly.

"It's simple, if I can simplify arithmetic, then you're going to have to help me solve one, no! It's two puzzles, and you can rest assured that both of them are related to arithmetic and astronomy, which you are best at! When Li Su said this, he smiled like an old fox who had stolen a chicken. (Your support on this site is my biggest motivation.) )