"Mumumu……"

"What happened? Tetra"

Tetra smells my body for some reason.

Did you eat anything that smelled yesterday?

"The smell of a woman"

Really?

Your nose is too good.

"Actually yesterday ..."

When I told him about last night, he frowned.

"Suspicious. Absolutely dangerous for the woman. Don't get close."

"I guess I was suspicious, but it didn't look dangerous at all."

Rather, she was an unguarded girl.

It seemed to be able to push down with room. I don't do it.

"Woman's intuition"

"What's that"

At least in my experience, I've never felt a woman.

However, this world has a curse and a blessing.

Maybe there's some news from insects. The feeling of a woman is also appropriate ...

"Let's be careful!"

"That's no use. I'll follow you."

"It's Tetra that said it was dangerous. I'm the only one and I don't have to come."

In fact, the advantage of the land lies with me walking in the forest every day.

Recently, my feet have become quite fast, thanks to my improved physical abilities.

It's easy to escape alone.

However, if you have a tetra, you will need to carry it at worst.

"Uh ... then there's no help."

Tetra withdrew easily.

Tetra is recognizable and helps. If you think I'm right, I'll pull it right away. If you think it's not correct, it will give you an opinion.

If this is Ron and Rosward, they will whine without getting down.

Conversely, I'm worried because Gram and So Young don't object at all.

I have to get the children to think for themselves.

What matters is the ability to think logically.

To train your ability to think logically ...

Do you teach that?

It's not necessary now, but it will definitely help.

It should not be a waste of time.

Well, how to teach ...

_______________

"Look at this first"

I write numbers on the ground in a language other than the area near here called Christian. The reason for writing in a foreign language is that there are no unique characters in this area.

"Read in order. Ron."

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

"Correct"

"I can read that much."

Ron said dissatisfied.

No, I don't know unless I check it.

Well, it's easy to memorize numbers in foreign languages.

There is also an excellent teacher (Tetra).

I continued on the ground and wrote:

One, two, three, four, five, six, seven, eight, nine, ten hundred

0 1 2 3 4 5 6 7 8 9 10

"What that"

"The numbers below are my hometown numbers, the top numbers are in Greece, and I want you to remember the numbers below."

"Why do you have such a trouble ..."

Children with openly dissatisfied faces.

Recently, she just learned from Tetra, but she complained why she had to do this.

"My hometown numbers are more convenient because my hometown has a lot of countries and each country has its own numbers. But this number-only Arabic numbers work around the world Yeah, that's how easy it is to use. "

Arabic numbers are very reasonable numbers.

At present, science and technology are more advanced in Europe than in the Middle East, but in the Middle Ages the center of science was the Middle East and the Islamic world.

I think there are various things as a reason, but there is no doubt that Arabic numbers are a major factor.

Regardless, the origin of the Arabic numerals is India.

"Hey"

Most of them are convinced but don't understand the meaning. In the first place, these children may not be able to understand the sense that the language is different depending on the country.

For them, the world is about their own village and the city-state to which they belong. Speaking of Japan, it is a prefecture, at most a local level. I don't have the opportunity to interact with foreign languages.

"What is the circle below this blank?"

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

"Is there nothing?"

Tetra asked.

Yes, I was waiting for that question.

There is no zero year in the Christian era. The beginning is a year.

Have you ever thought it was weird?

For this reason, some people mistakenly think that 101-200 AD is the first century.

Why is it so troublesome?

The reason is simple. At the time the AD was created, there was no concept of zero in Europe.

"There is nothing, but it is inconvenient to define it. For example, there are leaves here. How many?"

"one sheet"

"How many is this?"

I hide the leaves.

"... No."

"I say this is zero."

On the faces of children? Floats.

"The numbers start at one. I don't know what's wrong. Nothing is nothing."

"Yes ... then let's take this leaf as one. How many are this?"

I cut the leaf in half, throw away one and show everyone the half-leaved leaf.

"one sheet"

"No, the perfect shape of the leaf is just one piece? This half and half are combined to make one piece, that is, one half.

"????????"

Shit, it's going to be painful. It is common sense for modern Japanese that zero starts the number, so I don't feel so uncomfortable.

Not for these children.

"Let's do this."

I write a number line on the ground.

"The memory of this beginning is zero. The next is one. Then, between zero and one?"

"Isn't the beginning one thing in the first place?"

"Between the numbers?"

"I think one half is another one!"

"In short, it's two."

"Does it increase by half?"

Oh oh oh! ! ! !

"Well, don't you know?"

After all, how do I teach?

I ask Tetra which is the smartest of these.

"I can't figure it out, I don't understand ... In short, don't you think about numbers one by one, but in a flow like a single line?"

Uh ... maybe.

Don't think that difficult! !

But thanks to Tetra's remarks, some children's faces have cleared. Truly a tetra.

"I don't know what it means"

"Refreshing"

Rosward and Ron lean further. Apparently Tetra's explanation was confusing.

In the end, today's lesson ended with everyone convincing the concept of zero.

I can think of my future ...

_______________

One month has passed since I taught math.

Children learned that the sponge could absorb water, so that even the slowest child could master a single-digit subtraction.

By the way, the fastest to learn is Tetra, which is already capable of adding and subtracting three digits.

Rather, it seems that some calculations can be done originally.

The variability in proficiency levels is starting to emerge, making it difficult for me to teach alone.

So I tried to teach the child who can do the child who cannot.

To teach people, you really need to understand. There is no more effective review than teaching others.

However, Tetra seemed dissatisfied. He has a face that he doesn't want to do two-digit addition.

But I have only one body.

And ten more smart people are much more useful than one terribly smart person.

However, dissatisfied things seem to be dissatisfied things ...

"Done. Answer me."

"Okay. Um ..."

He decided to teach Mathematics to Tetra in his spare time, outside of class hours.

If you don't say it because you're unfair, it's more unfair if you just let yourself be a teacher and don't teach me at all. I'm in trouble if I don't have it. "

That's why I'm teaching it this way.

"Is all the question right? The three-digit addition seems to be perfect.

"Next four digits?"

"No, neither three digits nor four digits will change. Next is multiplication."

Even so, it's a multiplication and abnormal speed in one month.

Although it skips fields such as length units, it is a fairly fast learning speed.

After all it is the difference between the motivation and the ability of the person.

"Memorize this for the moment"

"What's this?"

"Memorization card"

I give Tetra a card with the multiplication table.

Cards are pretty big because they are made of wooden boards. It was hard to make.

"It's troublesome ... you can calculate by normal addition"

"It takes time. It is faster to memorize."

To be honest, the four arithmetic operations between single digits are almost memorized.

Perhaps when I was little, I was working hard with both hands, but now I can answer instantly.

Well, thanks to solving similar problems hundreds of times.

"But if you remember the multiplication table, the multiplication is almost done. The division is the same as the multiplication, so it's easy.

When this is completed, the four arithmetic operations are completed.

Daily life is not a problem as long as the four arithmetic operations can be performed.

Following the four arithmetic operations will be length, area, and volume calculations, and speed and distance calculations.

To be honest, this is more troublesome to teach than the four arithmetic operations. I don't know the unit of length or weight in this world.

It is true that there is a definition of the length of the earth, but it is a mystery whether this world is a sphere in the first place. Maybe strange power exists instead of gravity.

"Hey, Almus"

"What?"

It is still a bit uncomfortable to be called Almus. Because I'm usually called by either my brother or the leader. Only Tetra and Yulia call me Almus.

"Have you all done in your hometown?"

"Oh, yes ... all Tetra-aged children. Well, everyone starts at the age of seven, and it usually takes two years to learn multiplication, so I think Tetra is better."

"Do you all learn?"

"Oh, there's compulsory education in my country, it's a national right."

By the way, children have the right to education, but no obligation. It is up to parents to be educated.

"Why do you do that? You should be rich and monopolize your knowledge."

"That may be good for the privileged class, but there are many other countries in my world besides my country. The countries are competing with each other. You can't attract the right people? You will lose the competition. "

Education is a lifeline, especially for a capitalist society.

In addition, in conducting democracy, the people are ridiculous.

"It's hard"

"Yes ..."

You can certainly see that.

In this world, competition is not so intense. No matter how hard you try, it is likely that agriculture depends on nature. There is little return from efforts.

It depends on the person who thinks this is poor or quiet.

From a Japanese perspective, people in this world will seem too lazy. From the point of view of this world, the Japanese seem too fast.

...... The Japanese rush to live is one of the best in the world.

Although it is inefficient for working well.

I'm not in a hurry to live, but there are too many people alive to hurry ...

The story has gone wrong. I just became bitter.

"By the way, Almus"

"what?"

"When can I master the words?"

"... you may not know, but learning a different language is extremely difficult."

I, in contrast to the children, had difficulty learning.

It's still much faster than learning English.

"What about living with language protection?"

"Hmm, but I can't teach you math?"

"After all without the present"

"my mother"

I unexpectedly stroked Tetra's hair.

When I tried to let go of my hand for a moment, I came close.

this is good.

It has a nice and smooth feel.

Even without soap, this is the kind of hair that often becomes soft.

"Huh ... I have to do my best"

I sighed.