Chapter 182: Math Craze in the Special Training Class

When Zhao Jianguo carried the twins down from the roof, it was already broad daylight. The courtyard now had a few small stools arranged in a semicircle around an old desk. Several children sat there, gripping pencils and exercise books, their eyes fixed on the blackboard.

He Yushui was wiping chalk dust from the edge of the blackboard with a rag. She glanced at Zhao Jianguo and said softly, "Everyone's here; we're just waiting for you to start."

Zhao Jianguo nodded, handing the children over to a neighbor helping to watch them. He walked to the blackboard, picked up a piece of chalk, and drew a lopsided cube in the middle.

"I went over this problem with the twins last night," he said. "One drew a line, the other mimicked an angle. Nobody taught them; they just sketched it spontaneously."

The children all looked up.

"That line is called an auxiliary line," Zhao Jianguo said, using a ruler to draw it in the figure. "It's invisible, but it can simplify a complex problem."

Someone in the back muttered quietly, "The exam doesn't even test this."

Zhao Jianguo didn't stop, continuing to write the next step. "You'll encounter many things later that look chaotic, but they all have solutions. The key is whether you can think of that 'invisible line'."

San Daye's grandson raised his hand: "Teacher, what if we can't think of it?"

"Then look more, try more," Zhao Jianguo said, handing over the ruler. "This was made by Jia Dongxu; it's called the Gaokao-exclusive ruler. It has markings, can draw right angles, and measure angles. Don't underestimate it—it's an extension of the human mind."

The child took the ruler and examined it from all sides.

Zhao Jianguo turned and wrote on the blackboard: "How to break down the volume of an irregular object."

The room fell silent.

Some flipped through their books with heads down, others chewed on their pencil tips. A boy wearing glasses frowned, scribbled a few strokes on his paper, then rubbed them out hard.

Zhao Jianguo stepped down from the podium and paced slowly around the classroom. "Every problem you're learning now isn't for scores. It's to practice a skill—how to split a tough problem open and examine it layer by layer."

"But the factory foremen say we won't need this for work later," a lanky figure in the corner said. "Twisting screws, connecting wires—where's all this winding about?"

Zhao Jianguo stood firm. "Then tell me, when repairing a motor, how do you know if its inner parts are deformed? By eye? Or with calipers? Once you have the numbers, do you need to calculate?"

The other person said nothing.

"Knowledge isn't a trophy hanging on the wall," Zhao Jianguo said, tapping his desk. "It's something you can actually use in your hands."

At that moment, San Daye's grandson suddenly stood up: "Teacher, can I use Uncle Jia's machine? The box with a numeric screen I saw in the laboratory last time."

A stir rose in the classroom.

Zhao Jianguo laughed: "You mean the simple calculator? Sure."

He shouted toward the doorway. Jia Dongxu came in, holding a tin box. He opened it and took out a palm-sized device; the panel had several rows of buttons, and a glass screen in the middle displayed numbers.

"This is my modified version," Jia Dongxu said, placing the device on the desk. "Enter length, width, height, and it automatically calculates the volume. It can also store formulas."

The children gathered around to touch it.

"No grabbing!" He Yushui shouted. "One try each."

San Daye's grandson carefully pressed a few numbers. The screen flashed the result. He compared it to his own calculation in his notebook, and his eyes lit up: "Exactly! It's faster and more accurate than my own!"

Zhao Jianguo picked up the device, saying, "But it won't think for you. For example, if you're faced with a strangely shaped chunk of iron, how do you break it into regular shapes to calculate? That still requires your brain."

"Well..." someone asked, "What if the exam doesn't allow this?"

Zhao Jianguo squatted down, looking at the child who asked. "You can eat with chopsticks, right? If one day you lose your chopsticks, would you still eat?"

The child stared, stunned.

"Tools can be lost or taken away, but if you understand the principle, you can recreate them." He stood up. "We're not training rote memorizers; we want people who can solve problems."

The classroom gradually grew quiet.

Zhao Jianguo returned to the blackboard and wrote a new set of problems. The students lowered their heads to begin working, some drawing figures with rulers, others huddling together to discuss.

San Daye's grandson held the calculator, writing out the formula on scrap paper. After working it out once, he manually checked it again.

Zhao Jianguo walked over to have a look. "Did you notice anything?"

"The machine is fast, but when I do it myself I notice where mistakes creep in," the child said, looking up. "For example, a wrong unit conversion can throw off the answer by a factor of ten."

"Exactly," Zhao Jianguo said, patting his shoulder. "Tools are for verification, not for laziness."

Jia Dongxu, who had been listening at the doorway, interjected: "Next week I plan to make a projector that can enlarge figures and cast them onto the wall. That will make solid figures much clearer."

"Great," Zhao Jianguo laughed. "Then you can be the teaching assistant and do a live demo."

"But first I need a student assistant," Jia Dongxu said, pointing at San Daye's grandson. "This kid's quick—will he do?"

The child's face flushed red.

Before Zhao Jianguo could answer, a commotion came from outside. He Yushui walked into the courtyard with several young people, holding papers and pushpins. They pinned a large display board to the wall, which read: "Siheyuan Teaching Method National Promotion Pilot Plan."

The sunlight fell just right on the words "Mathematics Thinking Special Training Module."

The students in the classroom turned their heads to look.

"What's that?" someone asked.

"That's what we're going to do," Zhao Jianguo said, pointing toward the window. "It's not just about teaching in this room; we want more people to know how to teach and how to learn."

"Will it really work?" the lanky figure who had doubted earlier asked quietly.

"It's already begun," Zhao Jianguo said. "You're the first cohort."

The class-ending bell rang—actually, He Yushui had tapped a copper basin.

The children packed their schoolbags; some were still discussing the problem, others chased after San Daye's grandson asking how to use the calculator.

Jia Dongxu packed up the equipment, preparing to return to the laboratory. "Tonight I still need to tweak the program, hoping to make this device capable of drawing simple diagrams."

"Thanks for your effort," Zhao Jianguo said, seeing him to the door.

"Not tiring," Jia Dongxu grinned. "Hearing the kids call me Teacher Jia makes me happier than any bonus."

When most people had left, Zhao Jianguo stood before the blackboard and slowly erased the last problem with the eraser.

Chalk dust fell onto his cuff, but he didn't brush it off.

San Daye's grandson was the last to leave; before going, he gently placed the ruler back on the podium. He glanced back at the blackboard, as if trying to commit those lines to memory.

Zhao Jianguo noticed his action.

"Want to stay a bit longer to practice?"

The child nodded.

"Go get a new notebook." Zhao Jianguo opened the drawer, handed him a blank practice book, "I'll check it tomorrow."

The child took the notebook, returned to his seat, opened the first page, and wrote his name neatly.

Zhao Jianguo walked to the window.

He Yushui was leading the interns in adjusting the display board's position. The wind lifted the hem of her clothes, and she raised her hand to straighten the blown-askew pushpin.

Sunlight fell on the paper, casting a clear outline.

System Prompt silently appeared: Civilization Inheritance Degree reached 70%.

Zhao Jianguo didn't move.

He watched the child writing seriously, and suddenly recalled how the twins' fingers had traced through the air last night.

The same motion, different meaning.

At that moment, San Daye's grandson raised his hand.

"Teacher, I solved this problem with a different method; take a look and see if it works?"

Zhao Jianguo turned and walked over.

The child pointed to a diagonal line on the notebook, his eyes bright.

Zhao Jianguo bent down to look at the problem.

His finger slid slowly along that line.