End of the second floor, inside the room.

This is a very large room, with an area of dozens of square meters, all corners are cleaned, the bedding on the bed is newly replaced, and the air is filled with a faint fragrance of flowers, giving people a comfortable feeling.

Richard nodded in satisfaction and sat down at the table. Pandora walked straight to the soft bed, her eyes straight, as if she was a little enchanted, and sat on the bed with a "bang", without saying a word, she kept the same look, constantly in a daze.

Pandora has been like this for days.

And the reason for this is because, after spending the initial excitement of leaving White Rock City, Pandora thinks that she is very useless when she thinks about her experience in White Rock City. I can't learn anything well, I can't fight, it's really sad.

After some serious consideration, Pandora made a very solemn request to Richard, that is, she hoped to learn something really useful from Richard, and it would not be useful to save a similar situation in the future.

Really useful!

Pandora emphasized these four words in a particularly accentuated tone.

After some research, Richard realized that Pandora was not joking, but really thinking.

Something that really works?

What is really useful?

Combat skills are useful, but you don't need combat skills to do experiments, even if you are a combat master, it won't help you in any way, which is why Pandora is sometimes frustrated.

Is it useful to do experiments? It's very useful, but if you do experiments to make flowers, your combat effectiveness won't be improved in any way, just letting Pandora do experiments is actually a waste of Pandora's powerful combat power.

To be honest, many useful things are one-sided and limited, and can only play a role in one or several fields, and once they exceed this range, they will be of no use.

This is true even with scientific knowledge.

A man is powerful in the biological realm, but he is also at a loss to throw him into a machine factory.

If a person has made outstanding contributions in the field of mechanical production, it will be difficult for him to change careers to cultivate cells.

What is really useful, and what is something that can be applied anywhere without any limitations?

In other words, what is the essence of science, and what is the core of everything?

There is only one answer, and that is – mathematics.

Well, math.

At the bottom of the whole world, the whole rational, scientific world, there is an unshakable cornerstone, and that is mathematics. On the basis of mathematics, there will be knowledge of physics, chemistry, biology and other subjects.

The whole world, the truth of the whole world, every law and formula, is fundamentally constructed by mathematics.

For example, Newton developed Newton's second law: the magnitude of an object's acceleration is proportional to the force, inversely proportional to the mass of the object, and proportional to the reciprocal of the mass of the object;

i.e. F=m*a.

F=m*a, what a concise and sacred formula, nothing can be violated in the field of classical mechanics.

But why is this formula like this? Why was Newton able to say this formula so accurately, did he peel back the whole world and peek into the real world principle?

Apparently not.

Actually, the Bulls didn't see any of the world principles, and the reason why there was this formula was because he first defined F, m, a, and then combined them into a formula.

In the same way, if he likes, he can make the formula a little more complicated, such as F=d*t*g, or =5h*r*k*¥/2472, etc.

In this case, then all the basic concepts of classical mechanics may have to be replaced in order to explain the letters in the formula. But no matter what the basic concept looks like, in this system, the interior is self-consistent and can be used to explain the phenomenon of motion.

So, it wasn't Newton who discovered the principle of the world at all, but he came up with a hypothesis and then explained exactly the phenomena of the world.

In the same way, the rest of the disciplines are more or less like this, building the whole system from the top down, within which it is self-consistent, and externally it can explain the various manifestations of the operation of the world to the greatest extent.

That's how the whole technology came about.

First it is hypothetical, then verified, and finally it becomes a theorem.

Therefore, the famous philosopher of science Karl Popper proposed that the criterion for judging whether a theory (proposition) is scientific is falsifiability. That is, a theory, as long as it finds a phenomenon that does not conform to it, is not scientific, but until it cannot be found, it is scientific in the corresponding field.

Science never thinks of everything in the world, does not think it can explain everything, but only as a careful and rigorous way of exploring the world.

It can even be said that science is only an imagination, an incomparably rigorous, careful, interlocking imagination, and it is the truth until the flaws of this imagination cannot be found.

The reason why scientific imagination can be so rigorous, careful, and interlocking is because it is based on mathematics.

All imagination starts with the simplest mathematics, starting with the number operation of 1+1=2.

Only if you think that 1+1=2 is right, there will be integers, prime numbers, exponents, calculus, functions, relativity, nuclear physics, quantum science, and everything else.

Just as Newton defined F, m, and a, there is F=m*a.

No one has a glimpse of the principles of the world, but mathematics assumes and simulates the principles of the world.

That's math, and that's what is most useful.

If a person can learn mathematics well, then it means that he has the most powerful ability - the ability to see through the essence of the world.

Therefore, there are no top fields on the modern earth, such as rockets, satellites, nuclear weapons, and finance, that do not require mathematics.

Mathematics is what is really useful, the key to truth.

After much thought, Richard decided to teach Pandora math.

As a result, there is now a demonic Pandora.

Considering Pandora's foundation, Richard did not start teaching difficult knowledge, such as quadratic equations, geometry, definite integrals, and the like, and threw them aside, but started by choosing the elementary school difficulty on the modern earth.

Professor Richard's is ...... Four arithmetic.

To be honest, it is not all of the four operations, but a part of them, which is the absolute essence of mathematics invented by China in the ancient calculations and the Spring and Autumn Period and the Warring States Period - the unique existence in the world.

Well, ninety-nine tables.

One by one, one by one.

One two gets two, two two gets four.

One three gets three, two three gets six......

From the first day he left White Rock City, Richard taught Pandora all the Ninety-Nine Watches, and Pandora has been digesting it ever since.

One day, two days, three days...... As of today, it's been five days.

For five days, Pandora struggled to remember.