"This ......," Bishop Cole frowned, placing the white paper in the sunlight and taking a closer look at the 'symbols' on it.

Bishop Cole shook his head and asked, "What is this?"

"Number!" Serena smiled, "It's a number!"

People in this world have long found the laws of addition, subtraction, multiplication and division, and the opening square, the Pythagorean theorem, equations, etc. are often used in the construction of spell models.

Unfortunately, the world's numbers are still lagging behind, making calculations often cumbersome, both financially and in terms of spell research.

But there is no such thing as numbers, which can be changed, just like changing words and language, it takes at least one generation to change.

Fortunately, most of the people in this world are illiterate and can't do arithmetic, and it's not surprising that the nobleman can't do arithmetic, so it can only be said that his education is incomplete, or that he is obsessed with something, so he has no spare energy to learn arithmetic.

Because Cervantes couldn't count, and it was difficult to count, the maid planned to bring 'Arabic numerals' to the world.

Humans are decimal creatures, and unless they have extra fingers and toes, they will be decimal.

The main material plane has the same natural laws as the earth, and human beings are still ten fingers, so the arithmetic method of human beings in this world is still decimal system.

Bishop Cole was still confused, and the maid smiled and gave him a little explanation of the use of the numbers, and the old scholar suddenly realized and then fell into deep thought.

Edith, who sat next to Serena, had a look of pride on her face, and she had learned the handy number, and although Serena's sister said that she was only a 'discoverer' and not an 'inventor', it was a great achievement in itself to bring this handy number back to light.

After learning this kind of number, it was much easier for her to calculate the spell model and build the spell model, just like using the [Prayer Technique] to improve her intelligence.

"Are you the inventor this time?" said Bishop Cole, whose face flushed with excitement, made a rare joke with the maid.

Serena shook her head with a smile and said, "No, I'm just the discoverer, not the inventor, I just stumbled upon this kind of number, and I don't know which era or which country's number, in short, this kind of number is convenient, so I hope to popularize it." ”

"Oh......" Bishop Cole nodded, "So, what about the price?

"Tell them!" Serena pointed to the blank piece of paper in Bishop Cole's hand, "the discoverer of this number is my Serena Screaming Wind. ”

Bishop Cole frowned again and asked suspiciously, "That's all there is to it?"

The price they paid before was so great, and this time ...... Wrong!

Bishop Cole's eyes widened and he gasped as he looked at Serena and asked eagerly, "What else knowledge do you have in your hands?"

The maid smiled mysteriously: "What if I say that I am seeking the throne of God?"

As soon as these words came out, not only Bishop Cole, but even Edith, who wanted to get closer to her, but had some struggles in her heart, was also frightened.

Clenching the handrail, Bishop Cole took a deep breath and asked, "What do you mean? Do you want to compete with my lord for the priesthood? Then why do you tell me?"

Serena didn't answer, but shook her head and asked, "I'm just joking, but why are you asking me these questions?"

Bishop Cole fell silent, and Serena pulled Edith out in her distraction.

Bishop Cole looked at the back of the maid pulling his sister-in-law away, why did he ask her that?

Because he thinks that the head maid of the tragic wind family has this qualification!

Whether she had the mind or not, he had to report the matter to the King of Knowledge, and the stakes were high, whether it was the number or the question about the great ambitions of the head maid of the Sadwind family.

Sloe Mendes, who hasn't changed for a long time, is he going to make waves again?

Is the head maid of the Sad Wind Collar and the Sad Wind family a small pebble or a boulder...... Or is it a floating island, will it be waves, tides, or tsunamis?

It's scary to think about.

............

Cervantes was bored with the knife in his hand, and the knife was constantly thrown and caught, so bored that it was almost like mushrooms.

"Lord Maid, Lord Lord, Miss Edith!"

The servants passing by were saluting the three of them, and the maid was at the front, which made Cervantes feel a little complicated.

But it wasn't a big deal for him, and he might have forgotten about it, but without the lovely gold coins, Cervantes couldn't sleep well, and the maid said it was 'borrowing money', but it was unknown when it would be repaid.

He knew that the sad wind was very short of money, but wasn't this something that happened some time ago?

Although I can sleep with a soft thing in my arms every night, the milky-white, smooth skin doesn't look as comfortable as the cute gold coins......

"Whoa!"

Cervantes took the small cloth bag, shook it, opened it, and immediately became a husky.

After a few months, Cervantes has more than two gold coins, which is amazing!

"Ten gold coins, for the time being, I will pay you back ten gold coins every month, and when we get richer in the future, this number will increase. ”

Cervantes' smile froze on his face, "...... Huh, ten gold coins, ten coins—isn't that good?"

Cervantes turned his words to the side with a scowl and was relieved to see the maid turn her gaze to the side, looking at the back of the maid's head grinding her teeth.

Edith gave him a disdainful look, then changed to a look of adoration, her burning gaze fixed on the back of 'Sister Serena'.

'It's so beautiful!' thought the sister-in-law.

Then, as usual, Serena was on business, Edith was helping Serena with business, and Cervantes was sitting on the couch playing with the eleven gold coins like a husky - and the sound was super annoying!

Tuk Tuk!

Edith was glaring angrily at her brother, who had no image to speak of, but she heard a knock at the door and looked up, at which time Serena also raised her head and said, "Please come in!"

A young official pushed the door and walked in, and found that the Duke, the maid, and Miss Edith were all there, and he bowed and said, "Lord maid, the Knight of Watchman said that he had discovered an anomaly in the Black Forest, and it seems that the beasts were breeding too much and needed to consume the number, so ......"

"Is the beast tide coming?" Edith clenched her pen.

The young officer nodded and said, "According to Knight Kyle's judgment, I'm afraid so." ”

Serena bit her lower lip tightly, it was this time......

Serena let out a sigh, looked at the young official, and said, "Let the nobles and knights get ready, our bottom line is still Overwatch Town." Although the old duke is no longer there, but our Duke of Sorrow is still there, and we must believe in the Duke!

The young official glanced at Cervantes, who was sitting next to him, nodded and replied, "Yes, I'll go!"

After the young official left, Serena's face was cloudy, and Edith sat silently in her chair, and the atmosphere was very depressing.

"Cervantes!"

Serena, with a stinky face, called out the name of the black dragon.

The black dragon tilted his head blankly.

"Give me to fight off the beast tide, no matter what method you use, you must beat the beast tide back in one day!"

The maid's tone was somewhat intimidating, and even Cervantes hadn't heard her speak in that tone many times.

However, he was still a little unimpressed and didn't take things to heart.

"Oh, good. ”

Hearing Cervantes' perfunctory reply, Serena added: "Now is the critical period for the development of the Sad Wind Leader, if you miss it, the Sad Wind Leader will not be able to make money, which means that you have no money!"

"I'll be sure to repel the tide of beasts in one day!" Cervantes roared as if he had been beaten with blood.

The maid smiled and nodded, and Edith looked at her brother with hopeful eyes.

No matter how unreliable he is on weekdays, she hopes that he can lead the knights of the Sorrowful Wind Leader like her father, and once again protect this Sad Wind Leader!