"Lao Bi has also learned to write letters, is this to treat me as a pen pal?"

That night, Li Yi received a private message from Bi Gou, the secretary of the household department, who did not represent the household department.

The letter says two things.

"While crying poor, saying that there is no money, and at the same time I have to make up for military funds, which means that I don't want to make up for nothing."

Li Yi understood, and Bi Gou went around and around, turning a kind of entanglement into words.

"Ask me if I pay taxes on newspapers? Of course...... I can't hand it in. Li Yi saw the second thing and shook his head.

"Don't pay?" Li Chengqi helped bring the letter over, and in winter, there were oysters to be delivered, as well as other seafood.

"You can't hand it over, the newspaper belongs to the education and military mouth, giving more money to the post station, and at the same time helping the people to read."

Li Yi refused, citing two reasons.

The newspaper does not belong to his personal official, and it involves the mouthpiece of Datang.

"At the same time, I need more money to organize people to do things manually, and no matter how much advertising money the newspaper costs, it will take a long time to invest in what needs to be done."

Li Yi has his own calculations, and the money he makes from the newspaper will be used to do other things in the future.

Turning his head, he said to Li Chengqi: "Big brother, before the Yellow River freezes, let's see if we can freeze a batch of fish and shrimp from Laizhou and send them to Chang'an." ”

"How do you freeze?" Li Chengqi knows that frozen fish and shrimp are better than dried ones.

"That's it...... No, the temperature is not low enough, the water freezes slowly, and when the water freezes, the Yellow River is almost impossible to go.

You can wait for the weather to be cold again, catch fish and shrimp in Bohai Bay, take the ice cubes frozen in winter to fish, and use ice to chill them.

Back on land, prepare a mixture of ice and water on land, put the fish and shrimp in it, and freeze hard overnight.

Packed into sacks and transported by land, it was cold and the temperature was low, and the ice cubes were also ice cubes to Chang'an. ”

Li Yi vetoed the method of grabbing the time of water transportation on the Yellow River and changed it to land transportation.

The cost is high, and there are many rich people in Chang'an.

"Try it for my brother." Li Chengqi was tempted, mainly because he wanted to eat.

Then he pointed to the letter written by Bi Wei: "Compensate you for your military ......"

"In the future, when the tax is collected, there is also the rent that Zhuangzi should call it, and it will be deducted from it, when the deduction will be completed, and when it will be paid again."

Li Yi was familiar with this kind of thing, both sides had face, and the imperial court took advantage.

The military funds are given now, and there is printed money when they are lent out, and there is a lot of money every day.

Li Yi didn't plan to ask for that money, he wanted to be a prisoner, a captive of 50,000 yuan, and it would be considered a profit in itself.

As for the giant panda, it is currently a personal hobby.

"That's fine, Brother Yi writes a reply." Li Chengqi also thinks that the household department has taken advantage.

Li Yi quickly wrote a reply letter, telling Bi Gou that he would not pay advertising tax, and explained the operation method of military funds and handed it to Li Chengqi.

"Big brother, do you know abacus?" After doing this, Li Yi suddenly asked.

"It's a little bit, and it's not good at learning." Li Chengqi was a little embarrassed, obviously he would be a little bit true.

"Recently, I have nothing to do, so I looked for it, and there is a set of formulas that can make it more convenient for people to use abacus instead of learning problems."

Li Yi smiled, got up and took out an abacus from the box next to him.

Two beads on the top and five beads on the bottom.

"In fact, to calculate the relationship between catties and taels, it is not necessary to use the above two beads, one bead, with different calculation methods, to multiply and divide sixteen sufficiently.

However, addition and subtraction are relatively easy to learn, so there are two beads on the top, one represents five, and the five beads on the bottom are also five.

In this way, it is faster to add and subtract to calculate catties and two, and you don't need to learn more difficult, and the account room can be calculated. ”

Li Yi first introduced the use of beads, the above two beads are low ration for beginners, and at the same time, for larger counting calculations, more beads carry more.

After saying that, he took out a few pieces of paper with tables drawn on them, and wrote decimal addition, subtraction, multiplication, division, and hexadecimal.

Eleven in hexadecimal is eleven, and twelve is twelve......

"I'm going to print this out, print it separately, put an issue in the newspaper, and the rest need to be spread to all parts of Datang."

Li Yi put the form paper in front of Li Chengqi.

He did the addition, subtraction, multiplication and division of the base system by hand, which was very simple, but his speed was slow.

He is not proficient, he has never learned mental arithmetic, abacus has been learned in elementary school, and then he didn't need it, he forgot it.

Suddenly, I thought about it, checked the information, and pondered it myself, so that I could demonstrate it to others.

"You also pass on this kind of secret method?" Li Chengqi understands it, it is indeed not difficult, of course, Li Yi calculates all decimals and integers.

Now Datang has its own set of methods for playing abacus, and it is easy not to pass it on.

At the same time, it also needs a deeper foundation in arithmetic, and there are one problem after another, and practice according to the solution method in the problem.

Now that I have drawn a table on a few pieces of paper, I can understand it when I look at it, and then I practice, and I basically forget it.

"There is one more thing that benefits the people, one tael is equal to how many catties, I am writing now, this is one back six two five, one two is equal to 0.0625 catties.

This retreat is calculated by only one return, otherwise it will become 0.625 catties.

Two leave one two five, two two is equal to 0.125 catties, and he doesn't have to return one.

Three stay 1875, and three taels stay in the abacus position, which is equal to 0.1875 catties.

In fact, if I learn the mathematics taught in my Zhuangzi well, I can't use it at all, and if I take a pen, I can figure it out, and there is no problem with mental arithmetic. ”

Li Yi explained the formulas and contents of the two pairs of catties on the abacus position, and he felt that in ordinary daily life, his mental arithmetic was enough.

However, to calculate the compound interest of the donkey's rolling interest, mental arithmetic and pen arithmetic are laborious, unless you know how to do mental arithmetic.

Mental arithmetic itself simulates an abacus in the mind, just like playing blind chess without looking at the chessboard.

Anyone who can play chess, generally opening the game, without many moves, can simulate it in their minds.

The simplest explanation of compound interest is stocks, with a limit of 10%, 10,000 yuan, multiplied by 1.1 point, 11,000 yuan.

On the second day, it was 11,000 times 1.1 and 12,100 dollars, and on the third day, it was 1.1 million......

This thing is too hard to calculate with a pen, and it hurts to count it for a hundred days.

Li Yi thought about it, shook the abacus back and forth, and pulled it with his hand on the position of the beads on it, and returned to its position.

"Brother Yi, you rewrite, this abacus and method for my brother, practice for my brother at night."

Li Chengqi saw Li Yi's movements and felt handsome.

He was going to learn it first, and then ......

The next morning, Li Chengqi's eyes were a little swollen, and he didn't have time to apply a hot hand towel, so he hurriedly finished breakfast and ran away.

He first went to arrange the transportation of the Yellow River before it was frozen in winter, and then sent people to Laizhou to wait for the cold weather to try to transport the frozen fish and shrimp back.

If you want the Khitan side of Bohai Bay, the ice there is frozen in winter, that is, thin ice.

After dealing with it, he went to the imperial city, looked for Bi Gou, and took the letter with him.

When Bi Gou saw Li Chengqi, his eyes were on the abacus that was sandwiched under his arm.

"Bi Shangshu, the matter is done, I will reply to you." Li Chengqi handed the letter to Bi Gou first.

Bi Gou unfolded it and took a look, relieved, the way is good, and it will be slowly deducted from the tax in the future.

After reading the letter, he looked at Li Chengqi, King Song, why don't you leave? Still want to reply?

"Bi Shangshu, can you know abacus?" 'Wow, wow! Li Chengqi shook the abacus, placed it on the table in front of Bi Gou, and returned to its place.