Abandoned daughter takes charge of the family, so rich that even the best people can't envy

Cui Zixuan stood up and bowed to the seated emperor, empress, and princess before she spoke gracefully, "I am Cui Zixuan, the head disciple of the Xuantian Sect. I am proficient in astronomy, mathematics, and alchemy. Since Dr. Song is the chief doctor of mathematics, I dare to compete with him. I would like to ask for your guidance."

Song Jinxiu smiled and said, "Since you are a disciple of Xuantian Sect, then ask the questions."

She wanted to see how good her disciple's math skills were.

The eldest princess smiled and said, "In that case, I do have a question here, and I hope you two can help me with it."

She winked at Nanny Rong, and Nanny Rong stepped back.

She then asked Song Jinxiu and Cui Zixuan, "Do you two need anything?"

Cui Zixuan smiled and said, "All you need is an abacus, a pen and paper."

Song Jinxiu smiled, took out a piece of crumpled paper and a half-broken pencil from her sleeve, raised the things in her hand and said, "I just need them."

Cui Zixuan glared at him with disdain: "No need for an abacus, are you planning to do mental arithmetic? How ignorant! Is the question posed by the Grand Princess an ordinary one?"

She took the abacus handed to her by the maid, stood properly, and waited.

She never underestimates her enemies. Since the little girl wants to pretend, I'll let you be proud for a while.

Wouldn't it be embarrassing to ask for an abacus if you can't figure it out?

The emperor smiled and said: "Girl, can't you fold the paper neatly? How can you write on it if it's wrinkled?"

Nanny Rong quickly came in with a piece of paper.

Eunuch Hai, who was beside the emperor, took it and asked the emperor to take a look.

The emperor took a look and nodded.

Eunuch Hai said loudly, "Now there is an object whose number is unknown. The remainder of three times three is two, the remainder of five times five is three, and the remainder of seven times seven is two. What is the minimum number of objects?"

As soon as Eunuch Hai finished speaking, Cui Zixuan's abacus started to ring.

Song Jinxiu smiled, wrote a number and handed it to Eunuch Hai.

Eunuch Hai happily showed it to the emperor, and the eldest princess also took a look. It said 23.

The eldest princess didn't know the Arabic numerals, so she snorted coldly: "Hmph, you are just trying to be mysterious."

The emperor glanced at her and asked, "Sister, is the answer to this question twenty-three?"

The Grand Princess glanced at Song Jinxiu, who was listening intently, and said dissatisfiedly, "Royal brother, are you trying to tip off the little girl? You are the ruler of a country, you can't cheat."

The emperor laughed and said, "No, it was Minister Song who answered. That's the answer, so I asked you if it was twenty-three."

"What? How did she answer it without even calculating it?" The eldest princess looked at 23 with a look of surprise.

The emperor laughed and said, "Do you think my chief doctor of mathematics is a vegetarian?"

He glanced at the eldest princess's expression and said with a smile, "It seems that this answer is correct."

He glanced at Eunuch Hai and said, "Announce the results."

When Eunuch Hai's distinctive voice sounded, "The answer is twenty-three, Dr. Song wins,"

Cui Zixuan's face flushed red, she had only calculated halfway.

She didn't give up and was still making plans.

Someone asked, "Dr. Song, how did you figure it out so quickly? Did you calculate this problem beforehand?"

Song Jinxiu smiled and raised the crumpled paper in her hand. "I have already written down the algorithm. You can copy it down and take it home to study it slowly."

她的那张纸上只有几个阿拉伯数字：3x7+2= 21+2= 23

"Dr. Song, we don't understand this."

"Exactly, what is this? It's very roundabout."

All the people who came were girls, and not many of them knew Arabic numerals.

Song Jinxiu smiled and said, "If you don't understand, go home and ask your brothers who are studying at the Imperial College, and you will understand."

Someone hurriedly asked, "Your Majesty, can Dr. Song also give lectures at the Women's School?"

The emperor looked at Song Jinxiu and asked for her opinion.

Song Jinxiu then said, "Your Majesty, you can select two people from the princess's study companions in the inner study to teach at the Imperial College."

When the emperor heard this, he looked at Princess Mingzhu with a smile and said, "Let Mingzhu take charge of this matter."

Princess Mingzhu, who came with the Emperor and Empress, stood up with a smile and said, "Your Highness obeys your command."

After a stick of incense, Cui Zixuan finally came to the conclusion: twenty-three.

Cui Zixuan knelt down and kowtowed, "Your Majesty, I refuse to accept this. Dr. Song has solved this problem before, but this is my first time."

Song Jinxiu must have calculated it, otherwise she wouldn't have been able to come up with it so quickly.

Humph, this girl was too arrogant and didn't even pretend, which is why she was exposed. If she wrote down some calculations, perhaps she would not be able to find a reason to refute.

The eldest princess also said, "This is what I saw on an ancient monument. Miss Song may have calculated it before. But it is really impossible to determine the winner based on just one question."

The emperor frowned. He had seen the little girl's calculation speed before, but he wanted to make people convinced...

"Then what does the Emperor say?"

The eldest princess frowned. She didn't like math, and she came across this problem by chance. No one in the mansion could do it, so she took it out as an emergency measure.

Cui Zixuan stepped forward and said, "Your Majesty, I have a question. If Dr. Song can complete it within one stick of incense, I will be convinced."

"Oh? Lord Song, do you dare to accept the challenge?"

Song Jinxiu smiled and said, "Why not? Miss Cui, please feel free to speak up."

Cui Zixuan was secretly pleased with herself. She smiled slightly and said, "There is a five-foot-thick wall. Two rats are crossing it from opposite sides. The rat cuts one foot a day, and the rat also cuts one foot a day. The rat doubles its length each day, and the rat halves its length each day. When will they meet again? How much has each rat cut?"

This question was given by the Grand Elder of Xuantian Sect, and no disciple of Xuantian Sect could solve it.

She didn't figure it out at the time, but later she asked her master and spent another half a day to get the answer.

Moreover, she had changed a few numbers today. Even though Song Jinxiu had heard similar questions before, it would take time to do the math.

Cui Zixuan firmly believed that she would not be able to do it within an incense stick.

Cui Zixuan smiled and asked politely, "Does Dr. Song need an abacus?"

Song Jinxiu smiled and shook her head, saying, "I've already figured it out."

Cui Zixuan was stunned for a moment, then smiled and said, "Don't joke, Dr. Song. If you don't know how to speak frankly, I can teach you."

Song Jinxiu looked at her and said, "About two days, one hour, three quarters of an hour, and a quarter of a quarter later, the two rats met. When they met, the big rat had penetrated the wall by about three feet, four inches and seven inches, while the small rat had penetrated by about one foot, five inches and three inches. Is that correct?"

Everyone looked at Cui Zixuan, waiting for her to announce the result.

Cui Zixuan was confused because she had changed the original numbers in order to prevent Song Jinxiu from cheating.

So now she herself doesn't know the result of this question.

But Song Jinxiu spoke too quickly, and she found it hard to believe that the result she said was calculated by her. Yes, she must be making it up, she must be.

So she shook her head and said earnestly, "Dr. Song, mathematics requires rigor. Nonsense won't do."

Princess Kangning sneered, "Oh, so it was all just nonsense? I was so scared, I thought you were a god descending to earth. It's so fast, but it turns out you were just pretending!"

"Exactly. It seems she guessed the correct answer to the previous question as well."

The Grand Princess snorted coldly, "Hmph! Your Majesty, this is your beloved Minister Song. How can she be a role model for others if she speaks so recklessly? I think her position as Chief Doctor of Mathematics should be dismissed!"