My sister, whom I raised, has turned evil after faking her death for three years.

The living room was filled with a faint aroma of lemonade after dinner.

Su Qing leaned back on the sofa armrest, holding a small half-glass of lemonade in her hand, her gaze falling on the small figure across the coffee table who was doing homework.

Jiang Ran's pencil scratched names on the draft paper very quickly, almost without pausing. Occasionally she would stop and glance at the question before continuing to write.

Su Qing didn't pay much attention at first, until she accidentally glanced at the cover of the open exercise book—"Sixth Grade Math (First Semester)".

Her fingers paused for a moment on the rim of the glass, and a question mark slowly popped into her mind.

She hadn't even fully grasped the fraction word problems from fifth grade, and Jiang Ran had already started doing sixth-grade problems?

No, is that right?

The system calmly spoke in her mind: [Jiang Ran's learning talent rating is A+, and her cognitive development speed is in the top 0.3% among her peers.]

[Based on her ability curve, her progress in the sixth-grade curriculum is entirely within the normal range. In fact, her actual ability ceiling may be even higher. Based on the speed and accuracy of her completion of the most recent math Olympiad problem set, her logical reasoning ability has reached the level of a second-year junior high school student.]

Su Qing remained silent for a moment, then asked the system if there was any way to make Xiao Ran less obsessed with studying, and if going out to play and make more friends would be a good thing.

The system's response was concise and rational: [Based on Jiang Ran's behavioral data, learning brings her joy; her attention span, satisfaction upon task completion, and frequency of proactive learning are all significantly higher than the average for her age.]

[Based on system analysis, we do not recommend interfering with her self-directed learning. On the contrary, interrupting her learning will likely lead to an increase in her anxiety level.]

The system paused, a rare hint of genuine confusion in its tone. [Host, Jiang Ran clearly meets all the criteria for skipping a grade: exceptional cognitive ability, strong learning motivation, and excellent social adaptation. Why not let her skip a grade? At her learning speed, staying in the first-year classroom is truly a waste of her talent.]

Su Qing put the cup back on the coffee table, mentally organized her thoughts, and answered seriously: "Skipping a grade means she will have to sit in the same classroom with a group of children who are several years older than her, learn more difficult and numerous courses, and the amount of homework alone will be several times greater."

"Isn't primary school good? The current curriculum is simple and stress-free for Xiaoran, and she can go home every day. Look at her now, she learns so easily, like it's just play, and she even has time to make friends."

"Even Jiang Yi has been captivated by her, constantly following her around like a kitten. Isn't this kind of environment more suitable for her recovery than skipping grades?"

The system remained silent for a moment.

Su Qing could sense that the code had undergone a rather complex calculation deep within her consciousness.

Just as Su Qing had expected, the system was retrieving Jiang Ran's recent social behavior data, psychological state fluctuation curve, and stress hormone level change trend, and then comparing this data with what Su Qing had just said to draw a conclusion.

[The host's analysis is logically sound. Jiang Ran's social skills and mental state have indeed improved significantly recently, and a stable peer environment has played a positive role in this.]

[but--]

It paused, its tone still calm, but with a subtle shift in its wording: [Is the host certain that this decision has absolutely nothing to do with 'not wanting to start learning middle school math so early'?]

Su Qing paused for a moment, holding the cup, and replied somewhat guiltily in her mind, "...half and half."

[Understood. Half of it is genuinely for Jiang Ran's sake, and the other half is to avoid middle school math. However, according to system analysis, the proportion of the host's concern for Jiang Ran accounts for 90%.]

[Based on your behavioral data over the past three months, when facing decisions related to Jiang Ran, your altruistic tendencies far outweigh your selfish tendencies.]

[So although the host's fear of middle school math is real, the main driving force behind this decision was indeed out of consideration for her.]

  

Su Qing was too lazy to argue with it anymore.

Just as she pulled her attention away from her thoughts, she felt the sofa cushion next to her sink a little. Jiang Ran had moved from across the coffee table to sit next to her without her noticing.

The little guy was holding his workbook, looking up at her with a light in his dark eyes that Su Qing recognized very well—a light that always appeared whenever the little guy wanted her to do something.

She pushed the workbook in front of Su Qing, pointing to one of the questions with her fingertip, and said in a soft voice, "Sister, could you explain this question to me?"

Su Qing glanced down at the question.

It was an advanced math problem marked with an asterisk. The problem was very short, but when she read it for the first time, she only grasped a few keywords in her mind... score, construction team, cooperation efficiency.

She mentally called the system, which then recited the solution in a detached tone. She listened, then picked up a pencil and drew a crooked line segment diagram on a piece of scrap paper.

She spoke slowly, pausing twice in the middle. Once she miscalculated the work efficiency score, and the other time she forgot to simplify the fraction. She was only corrected after the system coldly reminded her.

Towards the end, she herself felt that her halting explanation was not very clear, but Jiang Ran listened quietly from beginning to end, occasionally turning her head to look at her with bright eyes.

After finally finishing explaining the whole problem, Su Qing put down her pen, feeling even more tired than if she had stood in a dessert shop all day.

The system promptly reported in her mind: [The host's explanation was about 71% accurate. There were two verbal slips in the calculation of work efficiency. Although the final result was correct, the intermediate process did not help Jiang Ran understand the problem.]

Su Qing felt like crying inside, thinking that she also wanted to give a good lecture, but asked the system to also analyze her own learning situation.

The system accurately analyzed a series of data, including Su Qing's weak points in mathematics, common error types, and a list of knowledge points that needed to be reviewed from scratch. Each item precisely hit her sore spots.

Su Qing really wanted to splash the remaining lemonade in her cup onto the system's face, but unfortunately, the system had no physical form and no face, so she could only swallow the pain herself every time she choked on it.

Jiang Ran took the draft paper, looked down and looked again at the not-so-straight line segment diagram her sister had drawn, then moved the workbook to the side, and then turned to the side, gently resting her head on Su Qing's arm.

She asked her sister to explain the problem to her, not because she didn't know how to do it.

She liked to see her sister's brows furrow slightly when she took the exercise book, liked to hear her sister's uncertain yet serious tone when she drew on the paper with a pencil, and liked the way her sister secretly breathed a sigh of relief after explaining a problem, but pretended to be calm on the surface.

Although my sister spoke haltingly, she was very serious about every word. My sister is not good at math, but I never refuse her requests.