Wang Ou found it interesting and said, "Can this set of symbols teach me?

"Of course." Li Mu squatted down, picked up a branch on the ground, wrote down nine numbers 1 to 9, and then left a blank space behind 9, writing 0. Wang Ou also squatted beside him and looked at it seriously.

"From 1 and up to 9, corresponding to one to nine, the 0 behind is zero. If you want to record a number that is larger than nine, add one in front." Li Mu wrote a '10' in the line below and explained: "The position of this 0 represents one. The digit added in the front represents ten. Now one here is o, which means no. The previous one here is 1, which means ten, which means 10."

Li Mu himself felt that he didn't explain it clearly, but Wang Ou actually understood it. He also took a branch and wrote a 15 on the ground, saying, "Does this mean fifteen? One ten, five ones."

"Yes, yes!" Li Mu nodded vigorously and said in his heart that he is indeed a daughter of a famous family, and he is indeed very smart. Li Mu took out the Arabic numerals just to use them. Since Wang Ou was curious and so smart, it would be the best for her to be her first student.

Li Mu wrote five symbols on the ground, '+''-''x''÷''=', and said, "When I was in Dingxiang, I read the "Zhoufeng Abbreviation Sutra" brought by my brother Li Siwen. After reading it, I felt it was complicated. The calculation technique recorded in it, and it was a simple question, so I had to write out several lines of words. It was really troublesome for me."

"This matter has always been in my mind. I thought I could find a solution after I arrived in Chang'an. When I lived in my foster father's house, I found several old accounts and asked me. They used calculation methods to calculate. Later, I worked in the Ministry of Works and found that the craftsmen who worked could not even use algorithms. They used the experience passed down from their ancestors to deal with the problems. They couldn't explain clearly how they calculated them."

Li Mu sighed: "I thought about it, it's not a solution to continue like this. So I invented this set of symbols for counting." Li Mu pointed to the ground and said: "After counting is feasible, I have repeatedly experimented countless times, invented these five symbols, and finally completed a set of my own algorithms. I call it the four algorithms."

"Fourth calculations? The algorithm you invented yourself?" Wang Ou's tone was full of incredible. She had learned the calculation scriptures and had learned more than one calculation scripture. The Wang family in Taiyuan has a rich collection of books. Wang Ou has studied since childhood, studied the "Zhoufeng Calculation Sutra", "Nine Chapters of Arithmetic", and "Island Calculation Sutra". Her arithmetic level, even if she participated in the "Ming Arithmetic" subject in the imperial examination, could easily rank among the top, so she knew the profoundness of mathematics.

All the existing calculations are the truth that only by sages and powerful people can we find after spending their lives and summarizing the experiences of our predecessors. And how old is Li Mu, he actually boasted that he had invented a set of algorithms?

Wang Ou is a little unbelievable.

Li Mu heard it and felt a little unhappy. If he talked about it, he would not dare to boast. When it comes to mathematics and numbers, he would still dare to say that he is proficient in it. In his previous life, he did data balance and dealt with numbers every day. Sometimes in order to correct a skill formula, he had to get up and work overtime in the middle of the night. He was very sensitive to numbers.

Even if he put aside his job, he is still a college undergraduate graduate. After passing the calculus, can he still not do the four-point calculation?

Li Mu smoothed the handwriting on the ground with his hands and said, "These five symbols represent addition, subtraction, multiplication, division, etc., five meanings."

"Addition and subtraction are very simple. The circumference calculation has been recorded above, but I found a simple calculation method for multiplication and division."

"There is a 'Nine Reason Song' in the Zhoufeng Calculation Sutra, which records simple multiplication formulas. For example, two, two, four, nine, nine, eighty, etc. However, it can only perform a few operations. If it is a larger number, it cannot be calculated. But with my symbol and my algorithm, no matter how big the number is, it can be calculated."

Li Mu wrote 23x18 on the ground and explained to Wang Ou: "For example, the number at the two ends of the symbol is called the factor according to the Nine Factor Song. We can use the single digit 8 of the second factor, first multiply the single digit 3 of the first factor, and get 24. We write it down, and then use 8 to multiply the ten digits of the first factor, and get 16. Because this 2 is in ten digits, we write 16 in front, so that we can get one hundred digits, two ten digits, and one single digit. We add the two numbers of ten digits to get 8, and we get 184."

Li Mu wrote down 184, and then continued to write below: "Then we use the ten-digit 1 of the second factor and multiply it again according to the method just now. Because this 1 is ten-digit, we get 23 tens, add 18 with 23 to get 41, and add 4 of everyone to get 414. How about it, isn't it very simple?"

Don’t look at Li Mu’s tedious words, but for the mathematics level of the Tang Dynasty, this was already very fast. So Wang Ou couldn’t believe whether the numbers calculated by Li Mu were correct. He kept these two numbers in his heart and planned to use the methods he had learned to calculate them again to verify whether Li Mu’s algorithm was correct.

"Let's talk about this division. Division can be regarded as the inverse calculation of multiplication. Just now we got 23x18=414, so we can divide 414 by 18. From the high position of the dividend, the divisor is a few digits, so we first look at the first few digits of the dividend. If it is not enough, we need to look at the extra digits. I call it the quotient', and the remaining number is called the quotient. The quotient must be written on which digit. The remainder obtained each time must be smaller than the divisor. After finding the highest digit of the quotient, if the quotient is not enough, the quotient is written on which digit..."

Li Mu has tried very hard to explain it easily, but he has long forgotten how the old dean taught him when he learned addition, subtraction, multiplication and division. Now he has long practiced the instinct of mental arithmetic. These steps are almost ignored when he calculates them, and there is really no way to say them simpler.

Ti Li said a lot, and Li Mu said that he was a little confused. He looked at Wang Ou who was squatting next to him and frowned and thoughtful. He felt very confused. He could understand.

Wang Ou didn't say anything for a long time, suddenly picked up the branch, wrote a 12x13 on the ground, and then calculated 156 step by step according to the multiplication of Li Mu's teachings. Then, according to the division of Li Mu's teachings, divided 156 by 12, and got 13." Li Mu clapped his hands so excitedly, grabbed Wang Ou's arm, and said excitedly: "You are so smart! You understand what I said so chaotic! It's so amazing!"

Wang Ou was grabbed by Li Mu and subconsciously wanted to retract, but when she saw Li Mu's excited look, a hint of hesitation flashed in her eyes and did not do so. This was the first time she was grabbed by a man with a voluntary arm, and a little strange feeling surged in her heart. However, she was no longer an ignorant girl, no longer had excessive shyness, but her cheeks were slightly red.

She used 12 by 13 because she just transported twelve vehicles of cloth yesterday, with thirteen pieces of cloth on each vehicle, and 156 pieces of cloth was actually found out by counting one by one. With this accurate answer, and then verifying Li Mu's algorithm, you can naturally know whether it is accurate or not.

The result surprised her. Li Mu's algorithm was so accurate and not bad at all. The seventeen-year-old man in front of him actually invented an algorithm himself. It was so simple that he could use it without knowing any math. How did he do it, such a great ability!

If there is really a genius who has come to this point, wouldn’t it be a joke for those who study the calculation of scriptures in this world to study the scriptures in their old age?

Wang Ou is not a person who is prone to anger, but at this time he couldn't help but want to give an explanation for the calculation scriptures that he had learned so many years when he was young. She thought for a while and suddenly remembered an unsolvable question in the Northern Wei Dynasty "Qiu Jian Jing of Summary" she read, which was called "Hundred Chicken Questions". Since the book was written during the Northern Wei Dynasty, no one has been able to solve this problem for more than 300 years.

Wang Ou didn't expect Li Mu to be able to solve it. She just wanted to attack Li Mu and see how he was frustrated. She didn't know why she suddenly had this kind of bad taste. She knew clearly that she was not such a person. Maybe after seeing Li Mu's surprise, she felt confused.

After making up his mind, Wang Ou told him about the "Hundred Chicken Question".

"Mr. Marquis, I have also read the calculation of the scriptures. There is a question I have not yet solved. I wonder if your algorithm can answer it?"

Li Mu didn't know what Wang Ou had to do, and thought she was still not convinced of her four calculations, so he said, "You said, I'll try it."

"There are roosters, which are valuable five; one hen, three, three chickens, which are valuable one. Buy a hundred chickens with a hundred dollars. Ask the roosters, hens, and chickens, which are the roosters, hens, and chickens?"

"Well... is this question?" Li Mu pondered for a moment, but he didn't feel the difficulty. He just felt strange. Has his mathematical level during the Tang Dynasty already started to study the system of three-element indefinite equations?

When Wang Ou saw Li Mu in a dilemma, she was delighted and finally stumped him!

"If it's too difficult, the marquis don't forget it. I'm just curious about this question. This question is ancient and modern..." Wang Ou wanted to say that even the masters of calculations have not calculated this question. It is not embarrassing to not calculate it. Before he finished speaking, he heard Li Mu say: "Four roosters, eighteen hens, seventy-eight chickens, or male **, eleven hens, eighty-one chickens. Or twelve roosters, four hens, and eighty-four chickens! There are three answers in total!"

"Ah?" Wang Ou was completely stunned. Li Mu not only gave the answer, but also said three answers.

Seeing her stunned, Li Mu was proud and said, "If you don't believe it, you can verify it."
Chapter completed!