Chapter 91
Chapter 91
Watching the scene, Su Qinghe grew uneasy. Had he known this would happen, he would have risen earlier and made more, sparing the Second Prince and the princesses any friction.
Zhu Xiaobiao leaned over and whispered in his ear, “Young Master Su, could you make more next time? I want my friend to try them too. I can pay!”
Su Qinghe froze and blinked in confusion.
This was the first time anyone had offered to pay him.
In the past, others had also coveted his food. They pretended to befriend him, and some even took his pastries to curry favor with other people, only to belittle him as worthless behind his back.
No one had ever paid him.
Su Qinghe shook his head. “There’s no need to pay.”
“How could that be? As His Highness says, labor and its results deserve proper compensation. Common people must be paid for their work, and even a friend who goes to the trouble of buying something on your behalf should receive a benefit.” Zhu Xiaobiao had picked up a great many new expressions from Xie Chengze and rattled them off fluently. He drew a tiny gold melon seed from his belt and secretly slipped it into Su Qinghe’s hand.
Zhu Xiaobiao had once lived in wealth himself and knew the ingredients in the pastries could not be cheap, so he did not stint on the price. “Young Master Su, whenever you enter the palace to see His Highness, just bring me one portion too~”
Su Qinghe stared blankly at the gold seed in his palm.
It was like a piece of burning charcoal, scorching his palm with heat and pain. He did not lack money and did not wish to accept it, yet he clenched the gold seed tightly. Even when the pain in his palm and fingers seemed to pierce his heart, he refused to let go.
He coveted the searing sincerity it represented.
And he coveted the bond that this gold seed could forge among them.
“Very well,” he said softly, a rare, genuine smile touching his lips.
Another wall collapsed.
In the end, Xie Chengze did leave some pastries for the two girls. He sent Zhu Xiaobiao to the kitchens for two food boxes so they could carry the treats back as gifts for their mother consorts.
Then he told them not to make a sound, pretended to leaf through an arithmetic book, and resumed writing his textbook.
He needed Su Qinghe to notice that he was working on mathematics. First deepen the impression, then guide him step by step. That would make it easier to persuade Su Qinghe to whisper in the Su family patriarch’s ear.
The two girls had long been curious about what Second Brother was writing. They crowded their small heads together, shoving each other as they peered closer, then asked in surprise, “Second Brother, when did you start studying mathematics?”
“Oh?” Xie Chengze looked up in surprise. “You know about mathematics?”
“Uh…”
Xie Shu and Xie Ping’an immediately ducked their little heads.
Xie Chengze: …
Xie Chengze understood. They dared climb the walls of Chenghuan Hall and even sneak out of the imperial palace. Naturally, they must have explored the Imperial Observatory from top to bottom too.
“Can you do mathematics?” He smiled at them.
The two girls shook their heads.
The corner of Xie Chengze’s mouth rose in a wicked, playful curve.
Now that he had transmigrated, how could he not check off the classic plot of “stumping ancient people with a famous math problem”?
“Then Second Brother will give you a problem~” Showing his little white teeth, Xie Chengze wrote the classic pheasants-and-rabbits-in-one-cage problem on the paper. “Pheasants and rabbits share a cage. There are thirty-five heads above and ninety-four feet below. How many pheasants and rabbits are there?”
The two girls eagerly began counting on their fingers. When that proved useless, they squatted on the ground and started drawing little pheasants and rabbits.
That quantity would probably keep them drawing all day. Xie Chengze lowered his head and resumed writing the textbook.
Zhu Xiaobiao watched for a while, grew restless, and joined the two princesses in drawing pheasants and rabbits.
Su Qinghe alone was left with nothing to do. He was wondering whether he should help the princesses like Zhu Xiaobiao when Xie Chengze finally seemed to notice his idleness. He handed Su Qinghe the pages he had already completed. “Qinghe, take a look for me. Is any of this difficult to understand?”
Su Qinghe felt as though he had been handed a hot potato.
He had never encountered a mathematics problem in his life. How could he possibly understand it?
But he was accustomed to yielding to others, so he steeled himself and lowered his head to read.
The first sheet contained the nine-by-nine multiplication rhyme. It was rhythmic and easy to recite, explained multiplication and division, and used a shop selling goods as a vivid, accessible example. It went on to show how to multiply and divide two- and three-digit numbers. The methods were clear at a glance, simple and interesting.
The second sheet contained large diagrams and strange little symbols Su Qinghe had never seen. Fortunately, every unfamiliar symbol was annotated, so it was not difficult to understand that they represented other things.
This symbol represented an angle. That symbol was an auxiliary notation. Combined, they meant…
The more Su Qinghe read, the more absorbed he became. The pages explained everything in plain, accessible language. Once he understood what the symbols represented, the shapes and numbers gradually assembled themselves in his mind. He lightly shifted one of the lines, and something seemed to explode. Countless new questions flooded his thoughts, leaving him desperate for exact answers.
It was like staring at pastry crumbs left on a tea table. If he could not find the answer, he would not sleep tonight.
He stole a glance at Xie Chengze, who had lowered his head and was carefully drawing with the help of a paperweight. Su Qinghe opened his mouth, then swallowed his question, planning to wait until Xie Chengze looked up.
Noticing the person beside him growing restless, Xie Chengze raised his eyes. “Do you need to pee?”
Su Qinghe: ?
His face instantly flushed scarlet.
How – how could the Second Prince speak so crudely?!
He shook his head hard. “N-no. I am merely confused by something on this page.”
“Oh?” Xie Chengze instinctively tried to lift his chair and move closer, forgetting that he was sitting on a stone stool. Only after grabbing it with both hands did he realize it would not move.
So he stood and walked to Su Qinghe’s side. One hand braced against the edge of the stone table, and the other settled on Su Qinghe’s left shoulder. Bending at the waist and sticking out his backside, he adjusted a nonexistent pair of spectacles, every inch the veteran schoolteacher. “What’s your question? Ask away!”
The young man’s shadow fell across the stone table and covered half the page. The pressure of the hand on Su Qinghe’s shoulder was neither heavy nor light, resting with exactly enough weight to command his awareness.
Su Qinghe stiffened slightly. Ignoring the shameful heat of being so close to another person, he extended one finger and traced the diagram three times. “If I move this line here and add another line here, making it… mm, making it stand up, would this theorem still be correct?”
Xie Chengze fell into a peculiar silence.
Why peculiar? Because this was a plane-geometry problem. With that one move, one added line, and the suggestion of making it stand up, Su Qinghe had transformed it directly into a solid-geometry problem.
Could this brother possibly possess the legendary innate sacred constitution for spatial geometry?
“That belongs to a different branch of mathematics.” Xie Chengze patted his shoulder gravely. “Stop looking at this for now. Go solve the pheasants-and-rabbits problem instead.”
Su Qinghe tilted his head slightly, rare insistence entering his eyes. “If I finish it, may I learn the answer?”
“Mm-hmm, mm-hmm.” Xie Chengze nodded perfunctorily. It was not that he refused to explain, but solid geometry was far harder for beginners. Without foundational knowledge, Su Qinghe would struggle to understand even if Xie Chengze taught him.
He would write a separate lesson plan later. The pheasants-and-rabbits problem would probably keep them occupied for several days anyway.
To his surprise, Su Qinghe’s soft voice sounded beside him. “Your Highness, there are twenty-three pheasants and twelve rabbits.”
Xie Chengze: ?
Xie Chengze: ???
Xie Chengze whipped his head around. “What did you say?”
Seeing such an intense reaction, Su Qinghe grew uncertain. “Is-is that wrong?”
“Holy shit, brother!” Xie Chengze seized both his shoulders in excitement. “Are you a mathematical genius?!”
Su Qinghe did not understand the expression, but instinctively shook his head in denial. The word *genius* had never belonged anywhere near him.
Xie Chengze refused to believe it. Two numbers flashed through his mind. After calculating the answer, he asked, “Then tell me this. Pheasants and rabbits share a cage. There are two hundred eighteen heads and six hundred seventy-six feet. How many of each are there?”
Su Qinghe considered briefly. Looking at the nine-by-nine multiplication rhyme, he traced something lightly on the stone table with one long finger. A moment later, he said, “There should be one hundred twenty rabbits and ninety-eight pheasants.”
Xie Chengze: !!!
Wait. He could solve even that?
“How did you calculate it?” Xie Chengze asked in utter confusion. Had Su Qinghe not said he had never encountered a mathematics problem?
“Mm, I do not know whether my answer is correct.” Judging by Xie Chengze’s face that it was, Su Qinghe finally dared explain. “Your Highness used this symbol to represent this angle. I thought perhaps the numbers of rabbits and pheasants could each be represented by a symbol as well. Your explanation of multiplication says that if a shop places four pastries in one food box, then six boxes, according to the nine-by-nine rhyme, give four times six, or twenty-four. That matches one rabbit having four feet: six rabbits have twenty-four feet.”
“The symbol for rabbits and the symbol for pheasants add up to the number of heads. Four times the rabbit symbol plus two times the pheasant symbol gives the number of feet.”
“A pheasant has two feet, and a rabbit has four – twice as many. If we treat the pheasant as having one foot, then the rabbit has two, and the total is halved. One rabbit symbol plus one pheasant symbol is two hundred eighteen, while two rabbit symbols plus one pheasant symbol is three hundred thirty-eight. The second exceeds the first by one rabbit symbol, so the rabbit symbol equals one hundred twenty. That means there are one hundred twenty rabbits and naturally ninety-eight pheasants.”
After finishing, he gave Xie Chengze a cautious look. “Your Highness, was I correct?”
Xie Chengze: …
Correct did not even begin to cover it, brother!
I wrote down a little addition, subtraction, multiplication, and division and labeled a few geometric figures ∠ABCD, and you already taught yourself to use ABCD in place of X and Y and solve the problem with something close to a linear equation in one unknown?!
His ability to infer and apply new principles was too damn powerful!