Chapter 37: A Lesson in Arithmetic

In the parlor.

Xiao Sizi stared at the ten symbols on the screen.

"Lin Xuan, what script is this? Neither the seal script nor the clerical script of Great Tang has such character forms."

"These are called Arabic Numerals," Lin Xuan raised one index finger. "Watch my hand."

Xiao Sizi's gaze shifted to his hand.

"One finger corresponds to this '1.'" Lin Xuan tapped that vertical stroke with his pen.

He flicked up two fingers, then three, in turn.

"This is 2, this is 3. They stand for the quantity of things."

"One apple, two oxen, three copper coins."

Xiao Sizi was exceptionally clever and grasped it in an instant.

She raised her own little hand and, imitating Lin Xuan, held up four fingers.

"This is 4?" She pointed at the symbol that looked like a flag.

"Correct." Lin Xuan nodded.

Xiao Sizi's gaze moved to the very first circle.

"And this one? How many fingers does this circle stand for?"

Lin Xuan drew his five fingers together into an empty fist.

"It's read as 'zero.' It means none, it means empty."

Xiao Sizi knit her brows tightly, tilted her head, and objected: "If it means 'nothing,' why bother specially inventing a character to record it?"

"If there's nothing, just don't write it—wouldn't that save trouble?"

Lin Xuan laughed. This was the very question he had been waiting for.

He flipped to a fresh page on the electronic canvas.

He switched to a red brush. On the left side, he wrote four traditional Chinese numerals: One, Two, Three, Four.

"Do you recognize these characters?" Lin Xuan asked.

Xiao Sizi puffed out her little chest.

"Capital-form numerals. The Ministry of Revenue keeps accounts with them, and so does the court when disbursing silver."

"To stop people from smudging and falsifying the books."

Lin Xuan picked up his pen and wrote on the right side: 1, 2, 3, 4.

"Look at these four Chinese characters—how many strokes does it take to write them?"

Lin Xuan pointed at the left side. "Writing the character for Four alone makes my wrist ache. Writing these four numerals takes me two seconds."

Xiao Sizi studied the comparison on both sides, lost in thought.

Lin Xuan continued the demonstration.

Beneath the screen, he wrote out a long string of Chinese characters: "Ten thousand, two hundred, and five."

"When you ancients keep accounts and hit an empty place, you have to write a zero character, or leave a blank space."

Lin Xuan wrote a string of numerals beside it in black ink: "10205."

He pointed at the two "0"s in the middle.

"Now do you know what this circle is for? Place-holding."

Xiao Sizi's pupils contracted.

"As long as this '0' holds the position—"

"These ten symbols, simply by their order in a row, can record quantities as vast as heaven and earth."

Lin Xuan went wild drawing circles after the 1.

"10 means ten."

"100 means a hundred."

"10000, ten thousand."

"Draw a few more circles and you get a hundred thousand, a million, ten million!"

Lin Xuan tossed down his pen and leaned back against the sofa.

"Just these ten minimalist symbols, lined up side by side—"

"One glance and you see ones, tens, hundreds, thousands, ten thousands, crystal clear."

"No need to write all those cumbersome radicals."

……

Great Tang.

The Ministry of Revenue.

It was the end of the month, time to tally the taxes.

Several dozen veteran accountants sat in the great hall, their abacus beads clicking away.

The desks were piled with account books half a foot thick.

Minister of Revenue Tang Jian was gripping a writing brush, laboriously inscribing "Sixty-seven thousand, four hundred, twenty-nine shi" into the ledger.

The voice of the Sky Screen came through.

Tang Jian instinctively looked up.

His gaze was locked tight on those two starkly contrasting lines of writing on the screen.

Ten thousand, two hundred, and five equals 10,205.

The abacus sounds had stopped at some unknown moment.

All the senior accountants in the main hall stood up, looking up at the sky.

"Place value... carry over..."

The brush in Tang Jian's hand slipped.

A drop of thick ink splashed onto the ledger, ruining half a page of records. He noticed nothing.

He stumbled out of the main hall and ran into the courtyard.

"Ten symbols... using only ten symbols!"

The Ministry of Revenue of the Great Tang manages the empire's household registers, land, taxes, and grain.

Every autumn harvest, ledgers from prefectures and counties across the land converge on Chang'an.

Those ledgers pile up like mountains, filled entirely with dense, capitalized Chinese characters.

Verifying a single account entry required several senior accountants to calculate for hours on abacuses, then copy every character one by one.

With the slightest carelessness, missing a single character or having unclear handwriting, the entire account became a dead entry.

Not to mention the corrupt officials and dishonest clerks below, who exploited loopholes in Chinese character writing to manipulate figures up and down, creating fake accounts to deceive the court.

Tang Jian looked at the extremely concise "10205".

A single stroke, beginning and end connected.

One extra zero means ten times the value; one missing zero means a loss of ninety percent.

This method of recording numbers is clear, fast, and possesses extremely strong anti-counterfeiting capabilities.

"My Lord!" An old accountant dropped to his knees with a thud at Tang Jian's feet, tears streaming down his face. "If all grain and money in the empire were recorded using this method, the Ministry of Revenue's accountants could finish ten days' work in one day."

"The audacity of corrupt officials to forge accounts will be shattered by these horizontal numbers!"

Tang Jian's eyes turned red as he rushed back into the main hall.

"Bring paper! Spread it out!"

Tang Jian snatched a fresh sheet of Chengxin Hall Xuan Paper and grabbed a brush.

He glanced up at the Sky Screen, then lowered his head to draw a stroke on the paper.

A circle, a vertical line, a curved hook.

Dozens of accountants in the hall woke as if from a dream.

They threw down their abacuses and grabbed paper and brushes.

The main hall was left with only the rustling sound of brushes racing across the paper.

The Ming Dynasty timeline.

Zhu Yuanzhang executed corrupt officials without hesitation.

The Empty Seal Case, the Guo Huan Case—he beheaded people by the hundreds.

All because local officials tampered with the ledgers.

"Write it down! Issue an edict to the Ministry of Revenue for us: carve these ten Western Regions ghost-drawn symbols onto wooden blocks and print them for distribution nationwide!"

Zhu Yuanzhang clenched his fists. "Henceforth, all Ming ledgers, whether for grain, money, or cloth, must use these ten symbols."

"If anyone dares to write those long strings of traditional large characters to fool us again, we will skin them!"

Modern apartment.

Lin Xuan watched Xiao Sizi's furrowed brow gradually smooth out and asked, "Have you figured it out?"

"The carry-over method," Xiao Sizi nodded, taking the capacitive stylus from Lin Xuan's hand. "Carry over when reaching ten; one unit down equals ten."

Her small hand held the pen, attempting to write on the bottom of the screen.

She drew a crooked "9".

Then, beside it, she wrote a "1" and a "0".

"After nine, with no new character to replace it, carry over to make ten."

Xiao Sizi lifted her face, her eyes filled with extreme excitement.

The rigorous logic of this numerical system gave her immense intellectual pleasure.

Lin Xuan clapped his hands and glanced at the wall clock.

"Clever. It took only half an hour to master the carry-over rules. The foundation of a Great Tang princess is indeed solid."

Xiao Sizi lowered her head and continued writing and drawing on the screen.

She wrote "99", then drew a horizontal line beneath it and wrote "100".

"Ninety-nine plus one produces a one in the hundreds place; the tens and units places both become zero."

She murmured to herself, as if discovering an extremely fun puzzle game.

Lin Xuan stood up and went to the kitchen to pour a glass of water.

Drinking the water, he walked back to the sofa.

The pen in Xiao Sizi's hand did not stop; the screen was already filled with various three-digit carry-over derivations. Although her handwriting was childish, the logic was flawless.