Why is the calculation speed of a serious calculation tool like Suanchou not as fast as the vertical calculation speed of pen column calculation?

It is said that the calculation speed of abacus masters is as fast as that of electronic computers. When New China was building the atomic bomb, because of the lack of computers, when calculating key data, they found a bunch of abacus masters and used abacus to knock out the data.

What's the problem? Why does Zhang Fei think that calculating tricks is not as fast as making vertical moves?

The difference between the structure of abacus and abacus is here.

When making calculations, you must first place the sticks one by one to count.

If you use abacus, if you move your finger lightly on the abacus, the abacus will move faster than the pen tip can write numbers.

As for counting chips, it is cumbersome to operate, and the movement of calculating chips is much slower than the convenience of just pushing the abacus.

There is no fundamental difference between abacus calculation and abacus calculation. They are both decimal and full decimal.

The difference is only in simplicity and speed.

In terms of speed, the gap between primitive arithmetic and mature abacus is as huge as a matchlock gun and an automatic rifle.

Therefore, Zhang Fei had been making calculations for a long time, so he might as well use a pen to do the math quickly, and a lot of time was wasted on making calculations.

The tip of the pen moves lightly, and several numbers are formed instantly. The calculation chip is picked up and put down for at least a second or two. This is why in the Han Dynasty, when there were no simple mathematical figures, pen calculations were faster than calculation chips.

Thanks to the Guigushen algorithm taught by Li Mengxi, Liu, Guan, and Zhang stayed up all night. All night long, the three of them set questions for themselves or each other, figuring out how big or complicated the numbers were.

One night, without any sleep, the three of them wrote on every piece of paper in a thick pile of paper, until the East became white.

It was daybreak, and the oil lamp that had been burning all night was extinguished.

Liu, Guan, and Zhang raised their heads and glanced at the bright red Chuyang in the east, "immerse yourself in learning, don't want the night to pass!" Liu Bei breathed a sigh of relief and rubbed his sore neck. He looked at his two sworn brothers with a smile on his face.

Liu, Guan, and Zhang looked at each other and then laughed.

After one night, Guigu's divine arithmetic taught by the military advisor has been fully understood.

Last night, the three of them calculated food and grass, troop strength, money, and marching distance.

But when it comes to military matters, we can calculate them one by one. Using the algorithm taught by Li Mengxi is fast and accurate. The calculation speed is several times faster than before.

Although they had not slept all night, Liu, Guan, and Zhang were still full of ideas and did not feel sleepy at all.

At this moment, Li Mengxi had not yet gotten up, otherwise, the three of them would definitely have asked for advice again.

If the three of them wanted to come here, it would be impossible to teach them all in one night.

——

early morning.

For some reason, there was an extra chicken during breakfast.

Is this... something so greasy to eat in the morning?

Li Mengxi was surprised.

Li Mengxi prefers to eat chicken legs. Liu, Guan, and Zhang have long understood this preference after being in contact with him for a long time.

Liu Bei tore off two chicken legs from the whole chicken and gave them directly to Li Mengxi and his two brothers.

During the meal, Liu Bei asked insinuatingly.

I asked if there is anything more difficult about the Guigu divine astrology I taught you last night.

It’s harder, yes!

Adding and subtracting multipliers is the most basic.

Further up, there are some mathematical symbols, such as square brackets, braces, squares, square roots, cubes, fractions, percent signs, thousandth signs, approximately equals, etc.

This is just simple pure numerical calculation.

Combined with practical applications, there are various application questions.

for example.

Example 1: You Liu Xuande took the people of Xuzhou and fled at a speed of 30 miles per day. Cao Cao was chasing the tiger and leopard cavalry behind him. The tiger and leopard cavalry were chasing him at a daily speed of 200 meters per day. It is known that Liu Xuande’s troops were behind the tiger and leopard cavalry.

First, they are one hundred and seventy miles apart.

Question: When was Liu Bei overtaken by the Tiger and Leopard Cavalry?

Ask again, at this time, seventy-five miles ahead, there is an important road where the army can be stationed to block the enemy.

Question, can Liu Bei's troops reach the dangerous place safely before being overtaken by the tiger and leopard cavalry?

Example 2: The title is: It is known that for a bow and arrow with the same strength, after the arrow is tied with a fire starter, the range is reduced to one-third.

It is also known that when there is a tailwind, the arrow speed is the sum of the wind speed and the arrow speed. According to the free fall theorem, it can be seen that if the wind speed is plus five meters per second, the maximum arrow range will increase by 2.35 meters.

It is also known that the east wind from Jiangdong is thirty meters per second.

Assume that the maximum range of a bow and arrow is eighty meters.

Question: If Prime Minister Zhuge goes to borrow arrows from a straw boat, how far away is the boat from Cao Cao's military base so that it can avoid the range of Cao Jun's rockets?

Ask again, how far away from the shore can the boat stop to borrow the maximum number of 100,000 arrows from Cao's army?

Third question, if the east wind blows, how far can Soochow's rockets reach Cao's army?

Example 3: It is known that the terrain near Fancheng is approximately a basin in the shape of a regular four-sided pyramid. Its base is a regular quadrilateral with a side length of eight miles, and it is surrounded by highlands with a side length of ten miles.

Fancheng Basin, from bottom to top, is 150 meters high.

Question: How many cubic meters of water can be filled near Fancheng?

The second question is, if General Guan stores water for an attack and floods Fancheng, and the water velocity at the breach of the river embankment is 30 cubic meters per second, how long will it take for the flood to completely submerge the Fancheng tower?

Right, to use mathematics to calculate practical problems requires proficiency in knowledge.

Algebra problems are only half of mathematics.

The other half is geometry.

The combination of algebra and geometry is the content of junior high school and high school.

Therefore, Liu Xuande asked if there was anything more difficult about Guigu's arithmetic. Li Mengxi put down his chopsticks and smiled mysteriously.

Then, Li Mengxi said in a deep voice, "The divine calculation in Guigu is filled with all things, from the stars, the sun and the moon, to the vast amount of sand, there is nothing that cannot be calculated."

As he spoke, Li Mengxi put on a serious look and bowed his hands in salute to Liu, Guan, and Zhang sitting on the opposite side, on the left hand side, and in the hall.

"If the three of you are willing to learn, I won't hesitate to teach you!

However, learning requires perseverance and avoid giving up halfway.

Mastering Guigu's arithmetic is not something that can be achieved in a short period of time. Can the three of you have such perseverance and perseverance?"

Li Mengxi deliberately used words to provoke each other.

Liu, Guan, and Zhang surrendered themselves to the case. They all stood up and saluted Li Mengxi, saying they were willing to learn.

Li Mengxi endured the hard work, and he was almost happy that he had deceived these three people with his mere mathematics knowledge.

Well, since you are willing to learn, mathematics is difficult to learn.

In this way, Li Mengxi, under the guise of Guigu's divine calculation, decided to teach Liu, Guan, and Zhang three other mathematical knowledge that was beyond the era of algebra and geometry.

Although, Li Mengxi has almost forgotten a lot of knowledge.

But under today's social conditions, it is enough.

While eating, Li Mengxi's mind was focused on something. Speaking of which, after learning simple addition, subtraction, multiplication and division, what should he learn now?

Application questions?

Or, what about direct geometry?

Understanding some knowledge and teaching knowledge to others and making others understand are two different things.

The only thing is that Li Mengxi does not have so many textbooks and teaching materials at hand.

Another point is, forget about algebra and geometry. When I first learned geometry, geometric proofs continued throughout my entire learning career.

Proof is important.

However, Li Mengxi was at a loss as to how each theorem was proved and derived. He might remember the theorem, but mostly forget the proof.

I couldn't help but stop using my chopsticks.

Junior high school mathematics textbooks introduce the Pythagorean diagram of Liu Hui in the Han Dynasty, which proved the Pythagorean theorem.

That picture...

Li Mengxi frowned and drew on the case.

How to draw it?

Or, where do you first start learning geometry? Points? Sets? Line segments? Then, the line segments are parallel, intersecting, overlapping, translation, etc., as well as parallel lines, internal and external angles, etc. After learning these, do you start learning triangles, squares and other figures?

Li Mengxi was overwhelmed with thoughts.
Chapter completed!