Bai Susu was surprised when he heard this, and asked, "What is a number symbol and what is it used for?" ”

Su Chen felt that the verbal explanation was difficult to understand, so he took out the smallest stiff brush from the pen holder on the table, dipped it in ink, and wrote down ten Arabic numerals "0, 1 to 9" on a piece ......of rice paper, and explained to her: "This is a mathematical symbol, representing zero, one, two to nine, eleven is represented by 11, and so on."

"Alternative?" Bai Susu is very smart and guesses how much it means.

Su Chen nodded and said: "That's probably what it means, we use these numbers to express different numbers through a certain combination relationship, the combination of two numbers is a ten-digit number, and the combination of three numbers is a hundred-digit number, for example, if I write this 124, it means that it represents one hundred and twenty-four, can you understand?" ”

Bai Susu pondered for a moment, nodded slightly, and said, "I can understand." ”

"Okay, you come and write a few times to familiarize yourself, and then I'll write you the numbers, you can read them!" Su Chen became a first-grade teacher in primary school, explaining to the smart and clever Bai Susu.

After Bai Susu carefully copied it a few times, he was able to correspond one by one, Su Chen wrote a few numbers on the paper casually, such as "23", "101", "964", etc., Bai Susu could recognize them and quickly answer correctly.

"Oh, yes, that's smart!" Su Chen looked at the delicate Bai Susu, and couldn't help but praise her with a smile.

Bai Susu smiled faintly, with an interest in learning new things, and said, "And then, what is the calculation method?" ”

Su Chen said: "Teach you a few more calculation symbols, this "+" is a plus sign, this "-" is a minus sign, when the big numbers are added, they can be written like this......"

After spending half a stick of incense, Su Chen told her the addition and subtraction symbols and calculation formulas, and then gave her some arithmetic problems, all of which were three-digit additions and four-digit additions, and made training.

Bai Susu has long had the thinking of calculation, but she is replaced by abacus and words, and now she has learned the calculation method of symbolic formulas, which is equivalent to having a good foundation, and she can draw inferences from one another in an instant, even if it is more than ten digits addition and subtraction, she can easily calculate.

"Addition and subtraction you have no problem, now we learn multiplication and division ......"

Bai Susu said with interest: "Is it the Ninety-Nine Multiplication Song?" ”

The multiplication formula has long been in ancient China, such as the cloud of "Guanzi - Light and Heavy": "The filter opera is made to make six mountains to welcome yin and yang, and the number of ninety-nine is made to meet the way of heaven." In "Han Poems-Biography", there is a cloud: "Qi Huan set up a court banquet, and people are not treated, and there are people who see it in ninety-nine." ”

In ancient times, the multiplication formula was from top to bottom, starting from "ninety-nine-eighty-one", so it was called ninety-nine multiplication table.

When Bai Susu was learning abacus as a teenager, he learned a little nine-chapter arithmetic from Mr. Private School, so he was quite familiar with the nine-nine formula.

However, there is still a difference between being able to memorize the ninety-nine formulas and mastering complex calculation formulas.

Su Chen wrote down the number "42x56" on the paper and told her how to calculate and multiply to get the final integer 2352.

"It's amazing!" Bai Susu's eyes lit up, and he could no longer maintain his previous calm and waveless expression, seeing this novel method of number operation, it was like Xu Dacai seeing good poetry, the old beggar Fan Jiugong seeing the wine, and Su Chen seeing the silver and long legs, showing a look of joy.

"You come and practice!" Su Chen wrote down a few multiplication numbers for her and asked her to calculate them herself.

After a while, Bai Susu quickly mastered this convenient calculation method according to his super comprehension ability, which was even better than an abacus.

"Division, too." In one breath, Su Chen explained the operation offensive and methods of division, and instilled primary school knowledge in modern mathematics to Bai Susu, which she quickly mastered.

"Next, tell you a statistical method, list some tables, and then convert the words in your accounts into numbers and list them, mark the entry and exit and surplus, so that the accounting and audit are much simpler."

Bai Susu was completely stunned, as if there was a feeling of clearing the clouds and suddenly opening up.

"So it can be like this!"

"There's nothing that can't be done, only the unthinkable!" Su Chen smiled slightly, feeling.

Bai Susu looked at him with a stunned look, pursed his lips and smiled, this person is good at everything in talent and personality, but he is a little skinny!

Su Chen was directly stunned, Bai Susu's perfect face, like a snow lotus, seemed to bloom suddenly in front of him, which was fascinating.

Bai Susu was stared at by his eyes, a little puzzled and curious, and he also greeted him and looked at him uncompromisingly.

At this moment, the faces of the two are close at hand, each other's breathing can be smelled, and their eyes are on each other at this moment, attracting, frozen!

Su Chen's mind was a little blank and distracted, moved by the appearance of the country in front of him, as well as the dignified and beautiful, graceful and luxurious temperament, his neck was a little bit forward, and his big mouth was close to Bai Susu's red lips.

Bai Susu's heart was also a little flustered, watching Su Chen's face get closer and closer, it was about to get close to her cheek.

She was unprepared and inexperienced, and she didn't even know what he was going to do. What should I do? I wanted to move my body, but for some reason, I couldn't move my body.

"Sister Susu, it's getting dark, has Su Chen woken up?" Peng Jingqing's shouts were heard outside the attic.

Bai Susu was interrupted by the voice, suddenly came back to his senses, avoided his body and stood up, Fang Xin was a little deer jumping, glanced at him, and then replied: "I'm awake." ”

Peng Jingqing continued to shout outside: "Let him hurry back to the house to prepare dinner, it's not early, why haven't you left yet?" ”

Su Chen smiled bitterly when he heard this, just now this girl shouted loudly, as if she had ruined a good thing for herself.

Just a little bit, his mouth can touch the lips of the cold and beautiful Bai Susu.

He really wanted to see how this cold goddess would react when she was kissed, and whether she would slap him in the mouth.

"Su Chen, hurry up and go downstairs and go home, Ling'er is hungry!"

There was also Peng Jingqing's urging voice downstairs, this time he was in the back of the pot.

If Su Chen hadn't been familiar with her and knew Peng Jingqing's character, he might have really believed him, but now, it must be her who is in a hurry to eat, and everything else is an excuse.

Why does this Peng Jingqing want to eat delicious food, the key is that although she can eat it, her body is still very slender, and her legs are so slender, you are not angry!

Su Chen waved his hand and said, "Su Su, then I'll go back to the house first, and after half an hour, you can pass." ”

Bai Susu nodded, and suddenly reminded: "Your amount of alcohol is much smaller than that of Qinqing, you can't fight her wine, be more careful next time, don't always get drunk by her." ”

Su Chen nodded, feeling that it made sense, if she was drunk one day and did something shameless to herself, her innocence would be ruined.