Leng Chan saw that the students all looked disappreciative, and a smile appeared on his old-fashioned face.

Only Li Changge shook his head, secretly saying in his heart that these students were only afraid that they would suffer a blow! This arithmetic problem is extremely difficult to calculate by conventional methods, let alone half an hour, and an hour may not be calculated.

However, most of the students looked like they were winning, picked up a brush and began to calculate on paper.

A few students found the problem, frowned, and thought to themselves that Mr. Leng was a middle-grade mathematician, and his mathematical attainments were quite shallow, and this seemingly easy problem was by no means that simple.

Time passed little by little, and the students quickly counted to the back, and in the sound of brushing, there was a gradual sound of surprise.

"The first day was one, the second day was two, the third day was four, the fourth day was eight, the fifth day was sixteen, the sixth day was thirty-two, and the seventh day was sixty-four...... The nineteenth day was two hundred and sixty-two thousand one hundred and forty-four, and the twentieth day ......"

Gradually, the students' faces became ugly, and even a few students stared at the numbers on the paper and doubted their lives.

"What's going on? Why does such a simple arithmetic become so difficult later on? ”

"This number is too terrifying, how can this be calculated......"

"I knew that Mr. Leng's question was definitely not that simple!"

"The number of the forty-third day is already a headache, and the forty-fourth day will be doubled again, how can this be calculated?"

Just when others were falling into self-doubt, Li Changge listed a method on a piece of paper, and after a simple calculation, he wrote a long string of numbers.

He shook his head, and secretly said in his heart, fortunately, I have read the book, and these questions are very similar to "Nine Chapters of Arithmetic" and "Sun Tzu's Arithmetic......

He just thought about it, and the book "Nine Chapters of Arithmetic" automatically came to his mind, and he began to turn the pages.

This can't help but surprise Li Changge, in his previous life, when he was in college, he also used his free time to flip through these two books, but it was only a quick glance, and he didn't expect this life to be clearly remembered in his mind.

"Is it because my memory has improved after crossing over?"

Idle is also idle, Li Changge simply flipped up "Nine Chapters of Arithmetic" in his mind, although they were all some math problems, but he watched them with relish.

Before half an hour had passed, most of the students had chosen to give up, Leng Chan on the podium glanced at the students, and found that even Li Changge had hurriedly calculated for a while and then sat in a daze, obviously giving up, he couldn't help but shake his head and sigh.

Everyone in Jiuding Continent wants to become a novelist, but arithmetic is abandoned, and even Li Changge, who wrote a work sought after by thousands of people at a young age, is not interested in arithmetic.

The loneliness of arithmetic has been a long time, but I am afraid that after the death of these old mathematicians, arithmetic will completely wither!

Thinking of this, Mr. Leng couldn't help but feel a little disheartened.

After a while, even a few students who had been insisting on calculating shook their heads and chose to give up, the further down the number, the bigger it became, not to mention adding it up......

When the time was over, Leng Chan stood up, looked at the ten students in the church, and said, "Which of you has figured it out?" ”

There was silence, no one spoke.

At this time, Li Changge had not read "Nine Chapters of Arithmetic", but he knew that Leng Zen was to teach these students who did not listen to the class, so he did not speak.

Leng Chan looked around and found that everyone else was a little embarrassed on their faces, and they didn't dare to look up at themselves, only Li Changge looked at the podium calmly.

Leng Chan was angry in his heart, and frowned: "Li Changge, I see that you look very sure, it seems that you have already calculated it, what is the answer?" ”

Other students all knew that Mr. Leng clearly wanted to find someone to vent his anger, and Li Changge became his punching bag.

If others would only laugh and laugh, but this cold old gentleman is very rigid and very serious, Li Changge is afraid that he will be scolded.

Xiao Liang, Yun Yanqiu and others were worried about Li Changge.

Li Changge was slightly stunned, then took a deep breath and replied, "It is equivalent to one thousand eight hundred and forty-four capitals, six thousand seven hundred and forty-four trillions, seven hundred and seventy seventy nine, five hundred and fifty-one thousand six hundred and fifteen. ”

After saying such a long string of numbers in one breath, Li Changge couldn't help but let out a long breath.

And Leng Chan couldn't help but widen his eyes, and picked up the paper on the table to compare.

The other students were also surprised, but they thought that Li Changge was talking nonsense, after all, how could it be calculated in such a short period of time?

Leng Chan stepped forward excitedly and said, "All right! How did you figure it out? Have you ever done this before? ”

The students were dumbfounded, weren't they? Really right?

Li Changge was a little numb by Mr. Leng's scalp, and said: "The student calculated it just now, and the formula is very easy to calculate......"

As soon as these words came out, Li Changge found that the eyes of the students converged, and he couldn't help but secretly forget that there are no mathematical formulas in this world......

"Good calculation? Is this called a good calculation? ”

"Isn't it? He can write novels, even arithmetic? ”

Leng Chan grabbed Li Changge's hand and said excitedly: "How did you calculate, show me the calculation again!" ”

Li Changge's heart was weak for a while, he used the formula for summing the proportional number series, and the formula had unknown numbers, so it was definitely not appropriate to write it down directly.

At this time, he saw Leng Chan looking at his paper, and hurriedly said, "Mr. Leng, I'll show you the math again." ”

He immediately took out another piece of paper to cover the original paper, and then took a brush and wrote on it the formula for summing the proportional series.

The letters in the formula are replaced by A, B, C, D.

This formula made Mr. Leng look dazed.

Li Changge said: "Substituting numbers into it, like this...... ...... like this"

He picked up a brush and counted a few times on the paper, and soon wrote out a long series of numbers: 18446744073709551615.

Leng Chan suddenly grabbed the piece of paper, stared at the formula on the paper, his eyes shot two fine lights, and his mouth muttered: "I see, I see...... That's a quick calculation...... Is this the formula? ”

Suddenly, he raised his head and stared at Li Changge: "How did you know this formula?" ”

Li Changge said: "The student had a dream before, dreaming that he appeared in another world that was completely different from the Jiuding Continent, and lived in that world for a lifetime, and this formula was also thought out at that time, and then he woke up from the dream and realized that the world was false......

Leng Zen said: "Like waking up from a dream, like a dream, have you received the guidance of a saint?" ”

Li Changge pretended to scratch his head blankly: "Maybe!" ”

Leng Chan continued to look at the formula on the paper, and suddenly laughed: "Li Changge, you are really a genius!" ”