They're already in university, and the primary school system is only just starting out?

Time ticked by, and Chen Lin typed the last line of code for the last function in Chapter Three, pulling himself out of a state of intense concentration.

He let out a long breath and looked with satisfaction at the full page of code he had typed himself on the computer screen.

Chen Lin glanced at the time in the lower right corner of the computer screen; it was just past 12:30.

"Good progress," he muttered to himself.

At this rate, I should be able to finish this book, "Python Mathematical Programming," within the next two weeks without any problem.

Then I can try to use programming combined with my "little mathematician" abilities to do some things.

I'm getting a little excited just thinking about it.

However, at this time, it seems a bit early before the time I agreed to meet Shen Yan at 1:30 pm.

Chen Lin thought for a moment, then simply closed his laptop and packed his things.

It's okay, just go there early and wait for her in the study room.

He left the library and, on his way to the mathematics department building, stopped at a convenience store and bought two meat buns and a bottle of mineral water for lunch.

Chen Lin has never been particular about meals. If he has time, he'll go to the cafeteria for a proper meal; if he doesn't have time or it's not on his way, he'll just eat whatever fills his stomach, like he is now.

He quickly finished his lunch and strolled over to the door of the familiar study room in the mathematics department building.

Just as I was about to push the door open and go in, my phone suddenly vibrated twice in my pocket.

This is a message notification from the Xianyu app.

Chen Lin paused, took out his phone, and opened it.

Oh, it's a new customer.

Black Whirlwind is not McFlurry: [Hello, are you there?]

Chen Lin raised an eyebrow and his fingers flew across the screen.

Seller: [Hello, what are your needs?]

Black Whirlwind is not McFlurry: [I have 14 fill-in-the-blank questions and 6 essay questions, how quickly can you give them to me?]

When Chen Lin saw the message, he was stunned for a moment, and then the corners of his mouth involuntarily turned up slightly.

This familiar question ratio, this classic "14+6" combination...

This flavor is way too strong!

Jiangsu Province has already switched to the national college entrance examination for mathematics, yet some teachers are still using old papers for surprise tests? That's insane!

Seller: [High school student?]

The message was sent out, and the other party replied almost instantly.

Black Whirlwind is not McFlurry: [How do you know?]

Chen Lin chuckled to himself.

Is it possible that I was young once too, and was also tormented by these kinds of surprise tests?

Most likely it was during lunch break or self-study period when the math teacher would suddenly drift into the classroom, throw down a test paper that was way too difficult for the curriculum, and announce in a sinister tone that it had to be handed in before school ended. Then, before the last class of the day ended, he would wait at the classroom door and collect the debt from each student who was carrying their schoolbag home.

At times like these, the top students in the class are probably all frowning, let alone the ordinary students.

Seller: [Answers are provided for fill-in-the-blank questions, and steps are shown for the longer questions. Total price: 880. Any questions?]

Chen Lin didn't bother with pleasantries and went straight to the price.

Black Whirlwind is not McFlurry: [How quickly can you give me results? Too slow and it's useless.]

Chen Lin glanced at the time at the top of his phone: 12:33.

Seller: I'll try to get it to you within half an hour.

I'll finish this order as soon as possible so that I don't miss my "consultation" with Shen Yan.

Black Whirlwind is not McFlurry: [Okay. Change the price, I'll take the order.]

Chen Lin was secretly pleased; it seemed they were really in a hurry.

He skillfully changed the price of the product to 880, and almost the instant he finished, the system notification sounded – 880 yuan received.

"Are all kids these days so outrageously extravagant?"

Chen Lin clicked his tongue, feeling a little shocked.

Back when he was in high school, 880 yuan was almost two months' worth of living expenses for him.

However, whoever pays the most is the boss.

Who cares what happens, just keep doing the problems!

Immediately afterwards, the other party sent several pictures in a row. Chen Lin clicked on them and saw that the lighting was dim and the shooting angle was crooked, but the content was very clear.

Haha, it really is a high school math exam paper from Jiangsu Province before 19.

He clicked on the first picture and his eyes swept over the fill-in-the-blank questions.

1. Given the function f(x) = ln(x + √(x² + 1)), its derivative f'(x) is expressed as ______.

2. In space, the edge lengths of tetrahedron ABCD satisfy: AB=CD=5, AC=BD=6, AD=BC=7. The volume of this tetrahedron is ______.

……

【14. Given circle C₁: x² + y² = 4 and circle C₂: x² + y² - 6x - 8y + 24 = 0, the equations of their radical axes are ______.】

For the average high school student, each of these questions would take them quite a while to solve.

But for Chen Lin now, fill-in-the-blank questions are a piece of cake.

He didn't even bother to find a draft paper; he simply swiped his phone screen, opened a blank notepad, and started typing rapidly.

【1、1/√(x²+1)】

【2、√95】

……

【14、6x+8y-28=0】

It flowed smoothly and was completed in one go.

He neatly arranged the answers to the fourteen fill-in-the-blank questions in his notepad. He took a screenshot and sent it directly via Xianyu (a Chinese online marketplace).

From the moment the other party placed the order and made payment to the moment he sent out the answers to these fourteen questions, the entire process took less than five minutes.

The moment the picture was sent, a message popped up on the other end in a flurry.

Black Whirlwind is not McFlurry: [Did you just fill this in randomly? You're not a scammer, are you?]

Even through the screen, Chen Lin could feel the other person's shock and disbelief.

Immediately afterwards, another message popped up.

Black Whirlwind isn't McFlurry: [Are you using AI? What kind of AI is so fast? Can you tell me? I can give you more money!]

Chen Lin looked at the message and sneered inwardly.

You're probably the second person to think that way.

He ignored the commotion, clicked on the pictures of the next few major questions, found a seat by the window, and took out paper and pen from his backpack.

He's going to start working on the more challenging questions.

……

……

Chen Lin wrote down the last number and gently put down his pen.

He rubbed his slightly sore right wrist with his left hand and exhaled a long breath.

Finished, that's it.

I checked the time on my phone's screen saver: 13:29.

Although high school math was no challenge for him, and he also had the enhanced physical fitness of a "Little Athlete," his wrists still started to feel a bit sore from writing out the solution steps by hand for nearly an hour straight.

He took out his phone, carefully photographed the several sheets of draft paper filled with writing, and sent them one by one in order of the question numbers.

After sending all the pictures, Chen Lin hesitated for a moment over the send button.

Considering that the person on the other end was a generous client, he decided to offer one more reminder.

Seller: [If your grades are usually average, it would be best if you corrected a few of your mistakes.]

Then he exited the Xianyu app and stopped responding to the other person's comments.

Because he had already noticed a familiar figure, carrying several books, quietly walking up to his side.

Sunlight streamed through the glass window, falling on her hair.

"High school level questions?"

Shen Yan's gaze fell on the several sheets of draft paper on his desk filled with formulas and derivations, and she asked softly with a hint of doubt.

"Yes." Chen Lin casually tossed the draft paper aside, leaned back in his chair, and answered easily, "The business I just took on is done."

He looked up, meeting Shen Yan's pure yet earnest eyes, and said in a slightly teasing tone:

"So, my big client, what problem have you brought me today?"