Chapter 36: Liu Hong's Showboating

Who was Liu Hong? He was a leader in the world of scholarship, sharing the top rank with Cai Yong. To have him personally offer to take one on as a disciple was like a massive, fragrant meat pie suddenly falling from the sky right into one's lap.

Fei Qian instinctively opened his mouth, then quickly snapped it shut. Hmm, why did this scene feel so familiar? It felt like those moments in a superior's office back in the modern era—a department head happens to drop by while you are finishing up some work, praises your competence, and casually tosses out a "Would you like to come work for me?" If you actually agreed, everyone would just laugh it off, and you would be left with nothing but an awkward silence.

Furthermore, this was the Han Dynasty, an era that placed immense importance on lineage and mentorship. The further back in history one went, the more critical these ties became. Unlike the modern world, where individuals go through countless teachers—primary, secondary, high school, university, language, math, not to mention physical education or substitute instructors—and thus the title of "teacher" loses its weight, in the ancient world, a person might only have one or two mentors in their entire lifetime. This difference naturally leads to a vastly different level of reverence for the position.

"Nearly fell into a trap," Fei Qian muttered to himself. "Liu Hong looks so dignified, yet he went and dug such a massive pit for me..."

Fei Qian bowed and said, "I thank you for your kindness, Master Liu, but I already have a mentor."

In truth, Liu Hong had not intended to set a trap; he had simply been caught up in the excitement of the moment. Once the words left his lips, he felt a pang of regret. Poaching a student openly in front of his master was awkward, even for an old friend like Cai Yong. Fortunately, Fei Qian had declined, otherwise, things would have been quite difficult.

Seeing Fei Qian’s response, Liu Hong decided to play along and act oblivious. "Oh? May I ask who your mentor is?"

At this, Cai Yong gave a dry cough. *Enough, Liu Hong, stop acting. I just told you that Fei Qian is my registered disciple and that I was the one who summoned him here. Who do you think his mentor is? You think Fei Qian is talented? I think so too, so don't even think about it.* Before Fei Qian could answer, Cai Yong spoke up, "Ziyuan was recommended to me by an old friend; we are fated to be together, so I have taken him as my disciple." Cai Yong intentionally omitted the word "registered," elevating Fei Qian to a full disciple on the spot.

When no one else was vying for him, Cai Yong hadn't thought much of it. But with competition, he realized Fei Qian was actually quite impressive. His appearance, though not as handsome as his own, was refined. His scholarship, while not on par with his own, had produced insights on mathematics that moved an old fox like Liu Hong—now that he thought about it, Liu Hong had always boasted about his mathematical prowess, and the fact that his own disciple had something that could impress him felt undeniably good.

***

Everyone, regardless of the era, has their own little schemes.

Liu Hong suddenly slapped his forehead and said to Cai Yong, "Oh my, I nearly forgot. I came here to bid you farewell. I shall be leaving Luoyang before long!"

"Why? You just returned not long ago, what happened?" Cai Yong asked in surprise.

Liu Hong replied, "I, unworthy as I am, have been appointed as the Administrator of Shanyang Commandery. Look, the official seal has already been issued." With that, he pulled the seal from his robes and showed it to Cai Yong.

A Commandery Administrator was a high-ranking official with a salary of two thousand shi. While Shanyang was not a massive commandery, it was by no means small. Cai Yong felt relieved and asked, "In that case, when do you depart? I shall host a farewell banquet for you."

"That would be wonderful. Let us say in a few days," Liu Hong replied without ceremony. He then pulled a square wooden box, slightly larger than a palm, from his robes and handed it to Cai Yong. "Come, take a look." His tone was that of someone showing off a rare treasure to broaden a friend's horizons.

Cai Yong took the box. It was crafted from ebony and finished with a layer of lacquer, looking quite exquisite. As he gave it a slight shake, it seemed there was something inside.

At Liu Hong’s gesture, Cai Yong opened the box. Inside, it was divided into three horizontal tiers. The top tier was the smallest, while the middle and bottom were larger. They were painted in black, white, and red to distinguish them. The box was also divided into nine vertical columns, which, combined with the horizontal panels, created ninety small compartments. Between each small compartment on the black and red panels sat wooden beads of corresponding colors—nine black beads and thirty-six red beads—while the compartments on the white middle panel remained empty.

"What is this?" Cai Yong frowned. He couldn't quite place the purpose of the box, yet for some reason, it felt strangely familiar, though he couldn't quite grasp why.

Liu Hong stroked his beard with a smug look, enjoying the sight of Cai Yong struggling to figure it out. *I put so much effort and thought into this clever invention; how could you possibly guess it so quickly?*

Fei Qian watched from the side, feeling as though he had seen this structure somewhere before, and tried to guess its purpose. One thing was certain: it was definitely related to mathematics. A man like Liu Hong would not be bored enough to present a mere toy as a treasure.

While lost in thought, Cai Yong picked up a black bead from the top tier and placed it into a compartment in the white middle section. He looked left and right, still unable to guess its use, then picked up a red bead and placed it in the white section as well.

***

Fei Qian’s thoughts suddenly shifted. Black beads, red beads, horizontal tiers, moving them to the middle... this pattern looked very familiar. A flash of inspiration struck, and he blurted out, "An abacus!"

Liu Hong, who was smugly stroking his beard, was so startled that he pulled out two strands of his own facial hair. He turned to Fei Qian and asked, "How did you know?!"

"An abacus?" Cai Yong repeated, murmuring the word to himself. He realized immediately that this was simply replacing the long counting rods with beads and arranging them in a box, like a tray. "Haha, indeed, it is an abacus. I had already guessed as much..." He maintained his composure, though he was secretly filled with admiration for Liu Hong’s ingenuity.

In the Han Dynasty, most people still used counting rods for arithmetic. The "strategy" in the phrase "devising strategies within a command tent" originally referred to these counting rods.

Counting rods were simply small wooden sticks. Depending on personal habit, they were used in two counting modes: horizontal or vertical. It sounds complex, but it simply meant whether the rod representing the number "one" was placed horizontally or vertically.

However, counting rods had inherent flaws: they were inconvenient to carry, easily lost, and if bumped during a calculation, they would scatter and mix together. Sometimes, if one had to stop a calculation to attend to a task, they might return and forget whether they were counting horizontally or vertically, forcing them to start all over again.

As a master of mathematics, Liu Hong had suffered these pains firsthand. Thus, after much deliberation, he invented this tool. He simplified the rods into beads, using red beads to represent one and black beads to represent five. The white section was for calculation, with each column representing a decimal place. Nine columns allowed for calculations up to the hundreds of millions, satisfying most counting needs.

This was the first time he had brought the finished product to show off to Cai Yong. He never expected that while Cai Yong failed to recognize it, Fei Qian would identify it in a single word. How could Liu Hong not be astonished?