Seeing Chunyan working hard to learn mathematics, Li Yuanjia was naturally very happy.

In fact, she and Liu Mei not only studied mathematics, as early as several years ago, the two girls have been following Li Yuanjia to read and write, it can be said that the accumulation over the years is not necessarily worse than those ordinary readers.

After all, living in the Han Wangfu, books, pens and paper and other resources are far from being comparable to ordinary readers, not to mention that Li Yuanjia is extremely generous to them, even the most expensive white paper is used by them at will, and the knowledge of the two girls is quite remarkable over time.

Maybe in terms of piano, chess, calligraphy and painting, they can't compare to ink painting and Si Qi, but they have to overpower the two little girls who married them in reading.

However, after seeing Cheng Erlang, Li Yuanjia's little happiness just now immediately dissipated without a trace. It's just that this guy immediately stepped forward and saluted when he saw Li Yuanjia, so that he had nothing to say - he didn't stretch out his hand and didn't hit the smiling person, not to mention that although this Cheng Chuliang was stupid, he was diligent enough, and Li Yuanjia was reluctant to give up on him.

Is it easy to find someone who is genuinely willing to learn Arabic numerals these days?

Especially the son of a prince like Cheng Chuliang, the son-in-law of the emperor, will be the lord of a mansion in the future! Even if you can't affect your parents and brothers, at least you won't have a problem influencing your children and grandchildren in the future, right? Not to mention that he and Princess Qinghe have at least a few hundred people in their families, and they are all potential users!

So even if he was impatient, Li Yuanjia had to greet him with a smile and patiently talk to Cheng Chuliang for half an hour!

"Yes, it's been going fast lately!"

After talking about all Cheng Chuliang's questions, Li Yuanjia pinched his nose and praised two sentences: "At your rate, the latest will be ...... Ahem, by this time next year at the latest, I should be able to finish reading these six books. ”

"Haha, really?"

After listening to his words, Cheng Chuliang's eyes suddenly lit up, and he asked in surprise.

“…… Almost! ”

The corners of his mouth twitched twice, and Li Yuanjia smiled dryly: "Hehe, but that's just after reading it, I'm afraid it will take longer to fully master these calculations...... Well, that's it, there's no end to learning! ”

With a smile on his face and an MMP in his heart!

Look at you stupid!

My buddy spent several years writing these six books seriously, and in order to allow the literati in the Zhenguan period to learn to use Arabic numerals and arithmetic without teachers, they did not hesitate to increase the length, and the content could not be more detailed......

Elementary school level mathematics, why the hell do you come to ask for advice in three days, and that's the result?

Forcibly suppressing the urge to complain, Li Yuanjia laughed dryly twice and then said with a smile: "Actually, Erlang must have found out these days, right?" This kind of Tianzhu number is a little more difficult to learn, but it is very simple to use...... Ahem, in fact, it's not that difficult to learn, it's just that we use Chinese characters to count in our daily lives, and we are not very used to it at first glance. ”

"Yes, yes, I think so too!"

After listening to his words, Cheng Chuliang nodded again and again: "Recently, I deliberately took out the account book at home and tried it, and after replacing all the numbers on it with Tianzhu numbers, the calculation speed is several times faster!" And after my father and eldest brother saw it, they also said that this Tianzhu number is good, and now let several account offices in the family also learn it......"

"What? Are you telling the truth? ”

Without waiting for Cheng Chuliang to finish speaking, Li Yuanjia's eyes widened and he asked urgently.

was a little inexplicable by his question, Cheng Chuliang smiled after a pause: "Why did the king say this?" Of course it's true, can this be fake? ”

"Uh......"

Li Yuanjia immediately knew that he had said the wrong thing, so he quickly smiled and waved his hand: "It's not that I doubt your words, it's true that I have written these six math books for a long time, but until now, in addition to you, King Wei is quite interested...... Alas, I don't understand, why don't many people want to learn such a useful Tianzhu number? ”

After half-truths, Li Yuanjia let out a long sigh.

It's true that not many people are interested in Tianzhu numbers, but Li Yuanjia still understands the specific reason - the ancients didn't have many opportunities to get "advanced mathematics", at most it was just to calculate accounts, so it can be completely solved with tools such as calculations, at most it is just a little less efficient. In addition, the pride in their own culture makes it difficult for them to accept such strange things as Arabic numerals, so even if it is not too late to enter China, it will not be until the nineteenth or even early twentieth century that Chinese really start to use Arabic numerals.

So even if there is one person who is interested in learning, Li Yuanjia will be very excited!

And......

Li Yuanjia knows that the Tang Dynasty is actually one of the most open dynasties in ancient China, whether it is religion, clothing, food, culture, etc., the Tang Dynasty is embracing many things from the outside world. And after the Tang Dynasty, starting from the Song Dynasty, it really became the "Heavenly Empire", not to mention accepting other people's culture, and even the road to communication was blocked a lot!

In other words, in fact, if you want to promote Arabic numerals, Datang is really a good time.

Relatively good times.

So complaining, Li Yuanjia was very excited about Cheng Chuliang's family's interest in Arabic numerals, and his eyes became extremely kind when he looked at Cheng Chuliang......

"Well, speaking of which, this kid is still my niece-in-law!"

Thinking of his niece Princess Qinghe, who married this kid when he was a little old, Li Yuanjia's heart suddenly moved. After thinking about it for a while, he opened his mouth and smiled: "By the way, Erlang, Lu Guogong went to Jiucheng Palace with His Majesty, right?" ”

"yes, I'm afraid it will be a few months before I get back."

"Hmm......"

After squinting and muttering for a moment, Li Yuanjia smiled and said, "In this case, if Erlang is free these days, you can run to me more!" It just so happens that I'm going to hold a garden party next month, right over there in the Hibiscus Garden, and Erlang can take Qinghe to take a walk with him. ”

After listening to his words, Cheng Chuliang suddenly became interested, nodded with a smile: "Garden party? That's a good feeling! Every day, I am either bored at home, or I am on duty, and I have long wanted to go out for a walk...... Hey? What does going to the garden party have to do with me coming to your house? ”

"Haha, of course it's to give you a chance to be in the limelight!"

After laughing, Li Yuanjia's eyes narrowed: "I made another fun game a few days ago, which is much more fun than that card, and it is the kind that can be played by many people." It's just that this new game is a little more complicated, and you need to use math when you play it, and the faster you do the math, the better, isn't this a good chance for you to be in the limelight......"