He was betrayed at the beginning, from a cake seller to a wealthy person

Lu Sheng also came back in the evening. His comment on the glass artifact was: Install one for me.

Lu Yan said that you will definitely have a share, all the rooms in our house will be equipped with it, and then an area will be allocated to me to build a school, and every classroom will have glass windows.

Lu Sheng raised his eyebrows: "Okay, let's build a college, right? This is the next job, right?"

"This is not my job, it's your job and the job of the construction workers." Lu Yan looked at him in confusion: "I can't do this job, I have other work to do."

Lu Sheng: "What else do you want to do?"

"I want to compile a book." Lu Yan said, "A book for children to learn to read and a book for beginners to do math."

Lu Yan believes that books for enlightenment are very important. Even if a person does not intend to take scientific examinations in the future, he should not be illiterate. He must at least master the recognition and writing of commonly used Chinese characters, and he must also be able to do simple arithmetic. In other words, he must at least be able to read and write commonly used Chinese characters. Learn things before the third grade of elementary school.

But now there are very few enlightenment books, except for Three Hundred Thousand. However, in Lu Yan's view, three hundred thousand is not a threshold for people who cannot read. As a result, many people cannot even enter the door of enlightenment and remain illiterate for the rest of their lives.

Modern society is impacted by electronic reading, and offline books, magazines, and newspapers are in decline. However, the only type of book that is not affected is children's books. The most popular types of children’s books among parents are preschool education and cognitive enlightenment books. When all parents buy books for their children, they hope that they will learn something from them.

The temperature is almost minus 20 degrees every day. Everyone is huddled in the house if they don't go out. It will take time to build the academy. During this time, Lu Yan plans to compile her own books and engage in preschool enlightenment education.

First of all, we need to compile a literacy book, using the modern model of corresponding pictures and texts, and can also include wall charts and cards. Secondly, we should compile a mathematical enlightenment book, starting with the recognition of numbers.

Lu Yan decided to introduce Arabic numerals. Numbers are the basis of mathematics. If Arabic numerals were not easy to use, it would not be used all over the world.

Lu Yan turned her gaze to Lu Sheng: "Friend, have you ever learned arithmetic?"

Lu Sheng was a little confused, but nodded: "I have read "Nine Chapters on the Mathematical Art" and "Sun Tzu's Mathematical Classic", what's wrong?"

Lu Yan was a little interested: "Did these two books talk about the problem of chickens and rabbits in the same cage?"

"Chickens and rabbits in the same cage?" Lu Sheng thought for a moment and recited a question: "Now there are pheasants and rabbits in the same cage. There are thirty-five heads on top and ninety-four legs on the bottom. How many pheasants and rabbits are there?"

Lu Yan patted her leg: "That's it. Forget the answer now and start from scratch according to the algorithm. Let's see who of us can calculate the result first."

Lu Sheng nodded, and just as he took out a pen and paper, Lu Yan had already given the answer before he had written two strokes on the paper: "Twelve rabbits, twenty-three chickens, right?"

Lu Sheng looked up at her in astonishment. She didn't even move her pen. She thought for a moment before holding her cheek and reported the answer.

Lu Sheng asked curiously: "How did you calculate it?"

Lu Yan cleared her throat and explained the problem to him: "There are 35 heads and 94 legs in the cage, which means that the total number of chickens and rabbits is 35, and these 35 animals have a total of 94 legs."

"Now let all the animals lift their two feet. 35 times 2 is 70. A total of 70 feet have been lifted. 94 minus 70 leaves 24. Now there are 24 feet left on the ground. The chicken only has two feet. Lift The two feet will be gone in the future. Now there are no chickens standing on the ground, only rabbits. Each rabbit still has two feet standing on the ground. This is 24, which is the number of feet of all rabbits standing on the ground. Divide by 2 to get the rabbit. number, so there are 12 rabbits in total.”

"The total number of chickens and rabbits is 35, there are 12 rabbits, and there are 23 chickens."

Lu Sheng was amazed and couldn't help but applaud. Lu Yan could always solve problems from angles he couldn't expect.

Lu Yan was also very proud. She had never thought that the Mathematical Olympiad she had learned in primary school, which she thought was useless at the time, would actually be used in ancient times. When she did those questions at the beginning, she didn't like to follow the examples. She always thought about it on her own and came up with some weird solutions.

Another question that left a deep impression on her was about water storage in a pool. The capacity of a pool is x, and a faucet is used to store water at x speed. A faucet is used to release water at x speed. How long will it take for the pool to be full while it is storing water and releasing water at the same time?

When Lu Yan was doing the question, she thought it was a crazy question. Who would store water and release it at the same time? Later, when she was charging her phone and playing, she suddenly realized the meaning of the question and thought she should change it.

It is changed to a mobile phone that consumes power at a certain rate per minute while playing games, and charges at a certain rate per minute. How long will it take to reach the target power level while playing games on the phone? Isn't this more reasonable?

Having gone off the rails, Lu Yan turned her thoughts back and didn't waste any time. She took a pen and paper and wrote down the Arabic numerals: "I have a new counting method. Using it, you can calculate the questions much faster. Take a look. ”

While Lu Yan was writing, she wrote down 0 to 9 and their combination rules for Lu Sheng. She also taught several two-digit addition and subtraction methods for Lu Sheng to experience on his own.

Lu Sheng learned multiplication by himself without any teacher, and immediately got to grips with the multiplication tables. The more he studied, the more motivated he became.

Seeing that he understood everything at once, Lu Yan taught him how to write vertical formulas, and he could calculate addition, subtraction, multiplication and division immediately. Lu Sheng was indeed the youngest scholar in the Dali Dynasty. He learned all the content before the third grade in less than an hour. Even Lu Yan could not help but marvel at his talent.

Lu Sheng raised his head excitedly: "It's really many times faster! You are simply a genius!"

Lu Yan quickly waved her hands: "Don't talk nonsense, this is not something I came up with, it's all other people's wisdom and has nothing to do with me."

Lu Sheng had heard Lu Yan say this too many times. Every time she came up with something new, she would quickly distance herself from him, saying that it was not her intention.

"I want to compile this into a book." Lu Yan said: "It is unrealistic for people who are illiterate to learn arithmetic. This is an easy way to get started and there is no threshold."

Lu Sheng touched his chin: "Do you think this should be reported to the prince?"

Lu Yan was stunned for a moment and thought for a moment: "Let's not leave it for now. Let's do a pilot project in Liaoyang first. If there are obvious results, we will report it."

Lu Sheng nodded, agreeing with Lu Yan's idea.