"Hurry up, I don't have so many rules here, you two just entered the city, you must have eaten yet, it just so happens that I haven't eaten either, let's eat together!"

Several servants quickly brought up the meal that had just been prepared, but Wang Bao was careful not to let go, Zu Chongzhi didn't care, he picked up the dishes and chopsticks and ate them, ignoring Liu Yuetian at all, and Wang Bao on the side kept making eyes at him useless.

Liu Yuetian didn't care, and said while eating: "I heard that Brother Zu is studying some arithmetic problems, and he is still studying pi, I don't know which number of centimeters has been studied?" ”

There is no decimal point in mathematics in this era, and the number after the decimal point is indicated in rulers, inches, minutes, centimeters, millimeters, seconds, and micro, but in the vast majority of cases, ordinary people do not use these units at all, and even they do not know that these numbers exist.

"Oh? Do you know pi? ”

Zu Chongzhi became interested all of a sudden, and looked at Liu Yuetian with his rice bowl and said.

"Understand, huh?"

Liu Yuetian smiled slightly.

A world-class physicist in a previous life didn't understand mathematics? His level of mathematics may not be at the top level in the world, but it is absolutely no problem to become a mathematics teacher in a world-famous university, as for the numerical level of the "folk amateur mathematician" in front of him, if it is placed in his time, even a primary school student cannot compare.

"Don't brag, I'm sure Xu Da said something about me, let me tell you, arithmetic is not a trick at all, it's a real knowledge, if everyone is like me, many things will be different."

Zu Chongzhi shouted, he thought the other party was teasing him.

"I'd like to ask, how did you calculate this pi, the circumcision?"

As soon as Liu Yuetian's three words of "cutting the circle method" came out, Zu Chongzhi's eyes widened.

"What? Are you calculating pi too? ”

"Sure enough, it's a ......... of the circumcision method."

In Liu Yuetian's previous life, the continuous accuracy of pi was not achieved by a certain person, but by a group of people who constantly used the circumcision method, that is, the number of sides of the circle was constantly multiplied in a circle, the closer the number of sides to the circumference of the circle, the closer the area of the polygon was to the area of the circle, and the more accurate the pi was naturally.

"So...... Brother Zu, how many sides have you cut? ”

Liu Yuetian asked again.

"Three hundred and sixteen sides, reaching the centimeter digits! Cut the fine, the loss is less, cut and cut, so that it can not be cut, then it is combined with the circle, and nothing is lost, although I am more accurate than the previous people, but it is still far from enough! ”

"It is very powerful to be able to cut 300 polygons with the power of one person, but I don't know how accurate it is!"

"If you can count the centimeters, then let me ask you, is the number on the centimeters five?"

Liu Yuetian asked tentatively?

"What? The ruler is one, the inch is four, the quantile is one, and this centimeter is five! How did you figure it out? ”

Zu Chongzhi jumped up all of a sudden, this inconspicuous four-digit number, especially the last two digits, it took him several months to figure it out, and he thought it was completely correct, he could calculate the centimeter, which was already two orders of magnitude stronger than the ancients, which can be described as a huge progress, in this era he thought he was the first person in the study of pi, but now the little prince in front of him actually said a word, is blind?

"I'm also doing random research, but it's a little deeper than yours, let me think about it......... After the whole digit should be 1315926......... The latter is too long to say. ”

"Whoa!"

Zu Chongzhi's rice bowl fell directly to the ground.

"If you know pi, you must know how to calculate the area of a circle!"

Liu Yuetian didn't care how surprised the other party was, and then asked.

"Multiply the radius of half a circumference to get ......... steps."

Zu Chong subconsciously replied.

"You can come to this conclusion, it seems that you already have a good understanding of the meaning of pi, so do you know how to calculate the volume of a sphere?"

"This ......... I've counted it now, but .........! ”

Zu Chongzhi's stunned gaze hadn't recovered from the shock, and he just replied mechanically.

"You watch!"

I saw Liu Yuetian stand up, pick up a piece of black charcoal, walk to a smooth stone erected next to it, and start writing.

Xiao Lu, Wang Bao and the other guards looked at the symbols that kept appearing and felt that they were looking at the Book of Heaven, even if it was Zu Chongzhi, some of them he understood, but most of them didn't understand, but even so, the various symbols written out of it were like priceless treasures in Zu Chongzhi's eyes.

"You...... You're calculating the volume of a ball......... How...... How so...... I...... I don't understand, but ...... Each step is a result......! ”

Zu Chongzhi couldn't read what the other party was writing, but the result was the volume of the sphere that he had been studying for several years but had never been able to break through.

Calculating pi is to use the circumcision method, then to calculate the volume of the sphere is to cut the sphere method, you need to cut the sphere into countless circles, this process is far more complicated than the plane of the circle, and even infinitely many circles to form a ball, how to add these circles to a whole is the biggest difficulty, Zu Chongzhi calculated for this bamboo slips as many as hundreds of catties, but still have no clue.

Liu Yuetian's calculation is the same as Zu Chongzhi's, setting a ball is composed of countless circles, these Zu Chongzhi can be understood, but the many numbers that originally made Zu Chongzhi uncontrollable have become extremely docile in Liu Yuetian, and lines of data were born in his pen, and in the end, he just used a strange symbol, and then directly came to a conclusion.

"The volume of the circle is ........."

"You must not understand this method, generally I call it calculus, you can combine an infinite number of circles into a sphere, or you can divide a sphere into an infinite number of circles, for example, pi can also be calculated like this......

This time Zu Chongzhi understood that Liu Yuetian assumed a circle with a diameter of one, and then ......... Let's say a 5,000-polygon was cut out of it.

And then......... Zu Chongzhi was a little incomprehensible, but in the end, the other party came up with a value accurate to the millimeter, which was one bit more accurate than the pi he had calculated for many years.

"Well, my calculus method is not bad!"

Liu Yuetian threw the black charcoal aside and said while washing his hands.

"You taught me this method, please!"

Zu Chongzhi grabbed Liu Yuetian's arm violently.

"This ......... It's just that this method is difficult to understand, I don't know if you can do it? ”

"Why not? My ancestor Chongzhi has been studying arithmetic all his life, and no matter how difficult it is, I have to learn it! ”

"Okay, then you can stay with me, but you can't learn in vain, I'm going to build a school, and the subjects I teach include mathematics, and you have to be a teacher."

"Ahh

Zu Chongzhi shouted directly this time, and simply knelt down in front of Liu Yuetian.

"Lord Wang! Only you understand me! You're my grandfather! ”