Chapter 9

"Hmm..."

"What's wrong, Tera?"

Tera, for some reason, is sniffing my body.

"Did I eat something smelly yesterday?"

"It smells like a woman."

Really?

Your nose is too good.

"Actually, yesterday..."

When I told Tera about last night, she frowned.

"Suspicious. That woman is definitely dangerous. You shouldn't get close to her."

"Really? I thought she was suspicious too, but she didn't seem dangerous at all."

She was rather unguarded.

I could have easily overpowered her. But I didn't.

"A woman's intuition."

"What's that?"

At least in my experience, a woman's intuition has never been right.

But this world has curses and blessings, so maybe there's something to it. A woman's intuition might be right... maybe.

"Then I'll be on guard."

"That's not enough. I'm going with you."

"But you said she's dangerous. I'll be more agile alone, so you don't have to come."

Actually, I have the advantage of knowing the forest well, and my physical abilities have improved, making me much faster.

It would be easy to escape alone.

But if Tera is with me, I might have to carry her on my back in the worst case.

"Ugh... Then I guess I can't."

Tera gave in easily. She's reasonable, which is a relief. If she thinks I'm right, she'll back off immediately. If she thinks I'm wrong, she'll give her opinion.

If it were Ron and Rozward, they'd throw a tantrum and refuse to back down.

On the other hand, Gram and Soyeon never object, which is worrying.

The kids need to start thinking for themselves soon.

The important thing is the ability to think logically.

To develop logical thinking...

I'll teach them this.

It's not necessary now, but it will definitely be useful in the future. It won't be a waste of time.

Now, how to teach it...

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"First, look at this."

I write numbers in Kyrshian, a language from outside this region, on the ground. I use a foreign language because this area doesn't have its own writing system.

"Read them in order, Ron."

"Um, one, two, three, four, five, six, seven, eight, nine, ten."

"Correct."

"Well, I can at least read that much."

Ron said this with a dissatisfied look. But I have to check, right?

Even a foreign language, numbers are easy to learn, especially with a good teacher.

I continued writing on the ground:

一、二、三、四、五、六、七、八、九、十 (Clearly a foreign language)

０ １ ２ ３ ４ ５ ６ ７ ８ ９ １０

"What's this?"

"The numbers below are from my hometown. The ones above are Kyrshian. I want you to remember the numbers below."

"Why do we have to do something so troublesome..."

The kids look openly dissatisfied. They've just learned the Kyrshian numbers from Tera, so they're unhappy about having to learn something new.

"The numbers from my hometown are more convenient. In my world, there are many countries, each with its own numbers. But these numbers—Arabic numerals—are used worldwide. That means they're more practical."

Arabic numerals are very rational.

While Europe is now more advanced in science and technology than the Middle East, the center of science in the Middle Ages was the Islamic world. One of the reasons for this was the use of Arabic numerals. Incidentally, the origin of Arabic numerals is India.

"Wow."

Most of the kids look like they understand but don't really get it. They might not grasp the concept of different languages in different countries. To them, the world is just their village and the city-state it belongs to—like a prefecture or region in Japan. They have no experience with "foreign languages."

"What's the circle under the blank space?"

"It's the number zero. It represents nothing."

"But if there's nothing, why is there a number for it?"

Tera asked.

Yes, I was waiting for that question.

There is no year zero in the Gregorian calendar; it starts with year one. Hasn't that seemed strange to you?

Because of this, many people mistakenly think that the years 101 to 200 make up a century.

Why is it so complicated?

The reason is simple: when the Gregorian calendar was created, the concept of zero did not exist in Europe.

"Nothing is nothing, but it's inconvenient not to define it. For example, if I have a leaf, how many are there?"

"One."

"Then how many are there now?"

I hide the leaf.

"None."

"I call this zero."

The kids look confused.

"Numbers start with one. It might seem strange, but nothing is nothing."

"Okay... Let's say this leaf is one. How many is this?"

I tear the leaf in half, discard one half, and show them the remaining half.

"One."

"No, that's wrong. The complete leaf is one, right? This half and the other half together make one. So this is half of one, or 0.5. Understand?"

"???????"

Damn, this is going to be tough. For modern Japanese, zero being the start of numbers is common sense, but it's different for these kids.

"Let's try this."

I draw a number line on the ground.

"The starting point is zero. The next is one. So what's between zero and one?"

"Isn't the starting point one?"

"Numbers have spaces between them?"

"Half of one is another one and one, I think!!"

"So it's two, right?"

"Does it increase when you split it?"

Damn it!!!

"Do you not understand?"

Maybe my teaching method is bad. I ask Tera, who is the smartest among them.

"I kind of get it, but not really... So numbers aren't separate, but a continuous flow like a line?"

Yeah... I guess so.

I never thought about it that deeply!!!

But thanks to Tera's explanation, a few kids' faces cleared up. She's impressive.

"I don't get it."

"Totally lost."

Rozward and Ron tilt their heads even more. They seem even more confused after Tera's explanation.

In the end, today's lesson ended just with getting everyone to understand the concept of zero.

The future looks challenging...

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A month has passed since I started teaching math.

The kids have absorbed the lessons like sponges. Even the slowest can now do single-digit subtraction. Tera, the fastest learner, can already do three-digit addition and subtraction (essentially long arithmetic).

She seems to have had some basic calculation skills already.

The differences in proficiency are becoming more pronounced, making it difficult for me to teach alone. So I started having the better students teach the others. Teaching others is the best way to review and ensure true understanding.

Tera, however, looks dissatisfied. She seems to think it's a waste of time to do two-digit addition now.

But I can only teach one at a time.

Besides, ten moderately smart people are more useful than one extremely smart person.

Still, dissatisfaction is dissatisfaction...

"I'm done. Check my answers."

"Got it. Let's see..."

Outside of class, I started teaching Tera math in my free time.

I said it was unfair, but she countered, "It's even more unfair that you only let me teach and never teach me. I'm teaching you language, so you should make some allowances."

I had to agree, so here I am teaching her.

"All correct. You seem to have mastered three-digit addition and subtraction. Shall we move on?"

"Next is four-digit?"

"No, three-digit and four-digit are the same. Next is multiplication."

It's an abnormal speed to be doing multiplication after just a month. Even skipping over units of length and other topics, it's an impressive rate of learning.

It's the difference in motivation and ability, I guess.

"Memorize this first."

"What's this?"

"Memorization cards."

I give Tera a card with the multiplication table written on it. It's a large wooden board, which was a lot of work to make.

"This is so troublesome... Can't I just do regular addition?"

"It takes time. Memorizing is faster."

Honestly, I've memorized most single-digit arithmetic operations.

I probably used both hands to calculate when I was little, but now I can answer instantly. It's the result of solving the same problems hundreds of times.

"But once you memorize the multiplication table, you're almost done with multiplication. Division is similar, so it's easy. You'll learn it quickly."

Once this is done, the four basic operations will be complete. With these, you can handle most daily calculations.

Next will be units of length, area, volume, and calculations involving speed and distance.

Honestly, teaching these will be more troublesome than the four basic operations. I don't know the units of length and weight in this world.

There's some definition involving the length of something on Earth, but I don't even know if this world is a sphere. Maybe some mysterious power replaces gravity here.

"Hey, Almus."

"Hmm? What is it?"

I still feel a bit odd being called Almus. Usually, I'm called "Brother" or "Leader." Only Tera and Yuria call me Almus.

"Do people in your hometown all know this?"

"Pretty much. Kids Tera's age all know it. They start at seven and usually take two years to learn multiplication, so I think Tera is more advanced."

"Do everyone learn it?"

"Yeah. In my country, there's compulsory education, which is a right of the citizens."

Incidentally, children have the right to education, not the obligation. The obligation to provide education lies with the parents.

"Why do you do that? Wouldn't it be better for the rich to keep knowledge to themselves?"

"True, that might be good for the privileged class. But in my world, there are many countries competing with each other. If knowledge is monopolized, it's hard to gather talented people, and you'll lose the competition."

Especially in a capitalist society, education is a lifeline.

Also, in a democracy, it's important that the citizens are not ignorant.

"It's tough, huh?"

"Yeah..."

That's one way to see it.

In this world, competition isn't as intense. Agriculture is largely dependent on nature, so the returns on effort are low. Some might see this as poverty, others as a peaceful life.

To a Japanese person, people in this world might seem too relaxed. To them, Japanese might seem too rushed.

...Japanese are known for living in a hurry, even though they work hard but inefficiently.

...Too many people live to hurry, not hurry to live...

I got off track. I started complaining.

"By the way, Almus."

"What?"

"When will you master the language?"

"...You might not understand, but learning a foreign language is incredibly difficult."

I'm learning much more slowly than the kids.

Still, it's faster than learning English.

"What if you just live without the language blessing?"

"Hmm, but then I can't teach math, right?"

"Guess I'll stick with it, then."

"Hehe."

I couldn't help but stroke Tera's hair. I thought she might pull away, but she leaned in.

This is good.

Her hair is so smooth and soft. It's amazing how soft it is without soap.

"Ah... I need to work harder."

I sighed.