Chapter 159: The Mental Arithmetic Master's Scratch Paper

When the bell rang, Zhao Jianguo moved his pen.

The first few questions were as easy as cutting tofu—he swept through them with a couple of swishes. He didn't hurry to flip ahead; instead, he nudged the scratch paper toward the centre, tapping his fingers twice on the desk corner, as if waiting for something.

Actually, he was waiting for his brain—just as that card entered his palm, a warm surge shot up his arm, and then his mind went 'click' as if a lock had opened. Numbers, symbols, and lines popped out on their own, lining up in his head with a faint sound.

He closed his eyes for three seconds; when he opened them, his gaze had changed—not fierce, but unusually steady, steady as a sinker that has hit bottom.

The final big problem lay at the bottom of the sheet—few words, but many traps. It was said to calculate earthwork for a water channel, also considering slope and schedule; it looked like a primary school word problem but actually twisted seven ways. For an average person, just setting up the equation would take twenty minutes.

Zhao Jianguo didn't rush to write the answer; instead, he lifted his pen and put a line on the scratch paper: 'Solution: let X be…'

He didn't write fast, but each stroke was neat, as if meant for someone to see. After finishing, he deliberately pushed the scratch paper half an inch to the right so the light would fall more clearly.

The proctor from the back row happened to walk over.

This man surnamed Li, whom everyone in the courtyard called 'Li Rules,' used to teach math at a middle school, correcting even the slightest crooked line in students' scratch work. Today he wore a gray cotton Mao suit, the cuffs frayed, moving silently, yet his eyes never rested.

He walked up behind Zhao Jianguo and, out of habit, glanced at the desk surface.

At that glance, his steps halted.

He had only meant to check for cheat sheets or secret signals, but his eyes landed on the scratch paper and refused to move.

What was written on the paper wasn't ordinary calculation. Terms like 'derivative,' 'limit approaching,' 'integration range'—words never seen in the textbook—filled it, plus a wavy-line symbol marked '∫' that looked strange.

Teacher Li's brows slowly knotted into a lump.

He lowered his head and glanced again at Zhao Jianguo's test paper—multiple-choice and fill-in-the-blank were all answered, the handwriting clean and neat, with not a single correction. Now the student was calmly moving on to the second question, right hand writing, left hand idly sharpening the pencil, a motion as familiar as if he did it every day.

'This kid…' Teacher Li muttered to himself, 'Where did he learn these?'

He said nothing, didn't slap the desk, just stood behind for a few extra seconds. But the longer the silence, the more it showed this wasn't simple.

Zhao Jianguo knew he was being watched.

But he didn't care. He didn't hide or conceal; instead, he spread the scratch paper wider, flipping over the back page too, which was densely packed with derivations, leaving no blank space.

Teacher Li finally couldn't hold back, leaning in to whisper: 'What are you writing? University-level stuff, right?'

Zhao Jianguo stopped his pen, lifted his head, and smiled: 'Teacher, I've studied ahead.'

His voice wasn't loud, his tone not aggressive—just like chatting about the weather.

Teacher Li choked, almost losing his train of thought.

'Studied ahead? You can study ahead into calculus?' He'd taught math for thirty years and had never seen a high schooler use partial derivatives as scratch work.

Yet a close look at Zhao Jianguo's expression showed he wasn't boasting. His eyes were clear, the corners of his mouth hinting at a smile, calm and unhurried, not smug—just as he said, it was nothing special.

Teacher Li could only nod, asked no more, and silently noted the seat number.

Zhao Jianguo lowered his head again, his pen tip never stopping.

After finishing the final verification step, he let out a long breath, checked the test paper from start to finish, confirmed it was error-free, closed the answer sheet, and neatly slipped it into the file bag.

The time to hand in the papers had just arrived.

He picked up his pen bag and stood up, casually slipping the scratch paper inside—not stuffed, but folded neatly and placed with aligned edges, meticulous.

Teacher Li came forward to collect the papers; as he took the bag, his hand paused, yet he still pulled out the scratch paper and quickly flipped through it.

The longer he looked, the more his brows furrowed.

'Where did these formulas come from?' he asked in a lowered voice.

'I saw them in a book.' Zhao Jianguo answered bluntly, 'I picked it up at a secondhand bookstore; the cover's fallen off, and I don't know which university printed it.'

Teacher Li stared at him for two seconds, then suddenly chuckled: 'You little brat… you're interesting.'

Having said that, he didn't stop him, only stuck a red label on the test cover and placed it alone in a kraft paper bag.

Zhao Jianguo turned to walk back; just as he sat down, his chest gave a light tremor.

A system prompt arrived: 'External illegal interference detected; logged for record.'

He didn't move or lift his head, merely tapping his fingers twice on the desk.

Outside the exam hall, Xu Da Mao hid in the wall corner, clutching a stack of tickets, while two youths in bell-bottom pants stood opposite him.

'Listen,' he said in a hushed voice, 'later, when no one's paying attention, sneak in and…'

He hadn't finished speaking when a large hand pressed down on his shoulder.

Don't move.

Officer Old Chen stood behind him, while another colleague had already subdued the two thugs, lifting each by one arm.

Xu Da Mao's face went white: 'I, I didn't do anything! I was just asking for directions!'

'Asking for directions led you to the back gate of the exam hall?' Old Chen sneered, 'You've got money in your hand and claim to be 'altering papers' on your lips—you sure know how to pick a spot.'

The two thugs immediately shouted: 'It was him who hired us! He said he'd pay fifty bucks to let us sneak in and switch the papers!'

'Shut up!' Xu Da Mao snapped, then realized he'd let slip, hurriedly covered his mouth, his face flashing green then white.

Old Chen couldn't be bothered to listen to his excuses, directly producing handcuffs: 'Come along; we'll chat slowly at the station.'

The commotion wasn't small; the exam hall windows were open, and many people heard the outside uproar.

Zhao Jianguo sat at his desk, his gaze lazily sweeping toward the window.

He happened to see Xu Da Mao being shoved into the car. The man struggled a bit, his hat fell off and he didn't bother to pick it up, his whole body hunched neck-down like a cat with its tail stepped on.

Zhao Jianguo drew back his gaze, neither smiling nor sighing, simply reaching into his pocket to feel the still-warm skill card.

The classroom was very quiet.

Other examinees were still heads-down answering; the sound of pen tips scraping paper whispered like sand. The ceiling fan turned slowly, its breeze carrying a hint of sweat and eraser dust.

He sat back in his seat, hands on his knees, back straight, eyes fixed on the edge of the blackboard where the countdown board hung.

Forty-three minutes remained.

Slanted sunlight streamed in, falling onto his empty desk.

The pen bag's zipper was sealed tight, the admission ticket number clearly visible.

From afar came the muffled thud of the iron gate closing.