“Bring in Mr. Nian.” Old Madam Qu made the final call. “Go fetch the ledgers from the storeroom—last year’s accounts for the Jing County workshop and the East City mulberry bark paper workshop. Get the ones from October to the twelfth lunar month.”

The final quarter’s books were notoriously difficult. Many delayed or unresolved transactions were rushed into the year-end accounts. Some lacked proper documentation, others skipped procedures, and some figures didn’t even match. Year-end accounting was a true test of skill.

Soon, Mr. Nian, the bookkeeper, arrived, drenched in sweat and hunched over. He was barely five feet tall (about 1.66 meters), with a triangular face. Perhaps proud of his scholarly status, he sported whiskers on both cheeks, a broad nose, and small triangular eyes like turtle-green mung beans—perfectly matched to his face. He looked like a rat with a long goatee. When he bowed to Madam Qu, his bald crown was fully exposed.

A rat with a goatee and a bald spot.

He Xianjin glanced at Madam Sun with a blank expression.

Wow. Thanks a lot. You matched me with a rat.

The ledgers were brought in. Old Madam Qu had two sets of tables and writing tools prepared. “Miss Jin will handle the East City workshop’s accounts. Mr. Nian will take the Jing County ones. The ledgers are real; only the final tallies have been removed. You’ll each calculate the monthly profit within one stick of incense. Let’s see who’s faster and more accurate.”

Just the profit? That’s basically a math test.

Difficulty level: instantly lowered.

Seeing the calligraphy brush, He Xianjin quietly pulled out her bamboo-tipped pen. “Old Madam, may I use my own pen?”

She studied business. She knew what a brush was—but the brush didn’t know her. If she had to use a brush to write complex Chinese numerals like “壹贰叁肆 (*),” she might as well give up—she’d end up submitting a sheet of ink blobs.

T/N: ancient numbers.

Old Madam Qu eyed the strange pen, recalled the neat writing in the previous ledger, and nodded. “Then let’s begin.”

Old Madam Qu’s attendant lit the incense.

Begin? He Xianjin frowned. “Old Madam, we don’t have…” She paused, then rephrased, “An abacus?”

Mr. Nian scoffed. “An abacus? That thing just came out. No one knows if it’s reliable or useful! It’s a novelty. You little girl must’ve heard about it from some shady source and now think you’re clever—bookkeeping isn’t for amateurs. It’s deep water!”

Feeling confident, he added, “Here are three words for you: go learn first!”

Just came out? He Xianjin recalled her university courses. The abacus did emerge during the Northern and Southern Song dynasties. There were records by the late Yuan. In Zhang Zeduan’s Along the River During the Qingming Festival, a tiny abacus was drawn on the counter of “Zhao Taicheng’s” pharmacy.

Wait—Qingming Festival Scroll. That depicted Dongjing, the Northern Song capital, as the most prosperous city. Back then, travel was slow, letters took ages, and even love lasted a lifetime—so the spread of new tools was equally slow. What was popular in a first-tier city could take decades to reach a remote county.

So what do you use for calculations? Mental math?

Her gaze drifted to the rat’s bald spot. Is that why you’re bald?

She restrained herself from asking.

The rat-like Mr. Nian proudly bowed to Old Madam Qu, then pulled twenty identical sticks from his sleeve. “Thanks to Old Madam’s favor, and my own diligence, I rely on these trusty tools.”

Counting rods! Damn! How could she forget those?

Before the abacus, people used counting rods—since the Han dynasty, for over a thousand years! Even Zu Chongzhi used them to calculate pi!

Turns out, even millet and rifles can beat cannons and planes.

With no abacus, He Xianjin had to rely on her nine years of compulsory education. She buried herself in formulas, quickly regaining the muscle memory of exam days.

Surprisingly, the ledgers weren’t hard. Income and expenses were stable—meaning the Chen family’s business model was consistent. Monthly purchases of raw materials like mulberry, bamboo, and lime were similar. Sales volume and types were steady. Wages hadn’t changed, suggesting a stable workforce. These were the easiest accounts to calculate.

What shocked her was that the mulberry bark paper workshop made a monthly net profit of 150 taels.

In this era, currency was copper coins: one coin = 1 wen, 1,000 wen = 1 string, 1 tael of silver = 1 string. Based on Chen Fu’s notes, a bowl of lamb soup cost 20 wen. She pegged that at 15 yuan in modern currency, so one string = about 700 yuan.

150 taels = 100,000 yuan in net profit.

One workshop, 100,000 yuan per month.

The Chen family had four workshops. Assuming East City was the most profitable, and estimating conservatively, their monthly net income was around 300,000 yuan. Annual profit: over 3 million.

With 3 million in annual income, Chen Fu barely qualified as a small private-sector rich kid—rich enough for a mansion, not quite for a Ferrari.

When He Xianjin filled in the final figure and looked up, the rat was still fiddling with his rods. Twenty sticks arranged in a strange formation, aimed at the “arrogant monster” across from him.

Unfortunately, Mr. Rat wasn’t one of those millet-and-rifle geniuses.

He Xianjin quietly turned her head and nodded to Old Madam Qu’s attendant. “Second Aunt, I’m done.”

Second Madam Qu’s attendant handed the ledger to Old Madam Qu. She scanned it and said coolly, “Mr. Nian, you may stop.”

Mr. Nian looked up in shock.

Old Madam Qu slowly closed the ledger. “Miss Jin has finished. Three months—all correct.”

Madam Sun gasped.

“She… she didn’t use counting rods! Or an abacus!” Mr. Nian protested. “How did she do it? It’s impossible!”

It was the multiplication table! The multiplication table defeated your little sticks!

He Xianjin mentally cued a dramatic anime soundtrack.

“I did the math here,” she said calmly, pointing to her head. “The greatest form is formless. The greatest action is effortless. To follow nature is to master it. Mr. Nian lost by trying too hard.”

That was a flawless flex. She gave herself full marks. Truthfully, it wasn’t a fair fight. People of this era hadn’t endured nine years of compulsory education. They didn’t understand the tyranny of math over Chinese students for eighteen years! Add four more years if you went to college and took calculus and linear algebra.

Regardless of the process, the result was: she won.

Old Madam Qu dismissed Madam Sun and kept He Xianjin behind. Her gaze shifted three times in mere moments. After a long pause, she spoke hoarsely: “Third Master is leaving for Jing County today. He still needs a bookkeeper. Would you be willing to go?”