Chapter 235 Mathematics
After breakfast, Su Ying picked mulberry leaves.
When the sun comes out, the dew on the mulberry leaves dries up, and they are at their tenderest again.
The tender mulberry leaves are as big as a palm. If you pinch them gently, white juice will emerge from the petiole.
If there were any extras, Su Ying would like to pick some to cook and some to dry and make tea.
There are many silkworms at home, so I have to focus on them first and not worry about tea and vegetables for the time being.
Although mulberry leaves are inconspicuous, they are very useful. They are not only the staple food of silkworms, but also have other functions.
It has high nutritional value and is rich in protein, vitamins and minerals. Its vitamin C content is higher than that of oranges and its protein content is similar to that of soybeans. It can be stir-fried, cooked into soup or used as stuffing, and can even be made into mulberry leaf jelly.
In terms of medicinal use, it has the effects of clearing away heat and detoxifying, moistening the lungs and relieving coughs. Eating mulberry leaves or making tea with them has a certain blood sugar-lowering effect.
However, it is not suitable for people with cold body, fear of cold, chronic heart failure, etc.
In just two or three days, the ant larvae grew a lot bigger, the gray-black color became lighter, and they were the size of rice grains.
It eats a lot, and mulberry leaves are added three times a day. Every day, a lot of mulberry leaf residues and silkworm feces need to be cleaned up.
Mulberry leaf residues and silkworm feces can be used as green manure after fermentation. When the silkworms reach the 4-5 age stage, their feces are even more useful.
At that stage, the mulberry leaves are fully digested in the silkworm's stomach, and the feces are high in nutrients.
Collect them, remove debris, place them in a ventilated and sunny place, add water, mix well, and ferment for 3-5 days.
Place the fermented silkworm manure in a well-ventilated place for 7-10 days to allow the organic matter in the silkworm manure to fully decompose and mature.
It is silkworm feces fertilizer, which cannot be used directly but needs to be mixed with other fertilizers before use.
After use, water the soil thoroughly to allow the nutrients in the fertilizer to fully dissolve and promote crop growth.
Silkworm feces is also a traditional Chinese medicine. It is mainly collected from the feces of the second to third sleep. After collection, it is dried and the soil and mulberry leaf debris are removed.
Silkworm feces can also be used to make pillows to improve sleep.
I returned to the silkworm room carrying mulberry leaves. There was no one there and it was very quiet.
After making breakfast, the three sisters-in-law had to feed the pigs, cows and horses, and they were too busy.
When Su Ying opened the door, she heard a faint rustling sound.
The ant silkworms were hungry and gnawed on the dry leaves in the winnowing basket, which was already covered with a thick layer of mulberry leaf residue.
"You really can eat!" Su Ying said with a smile.
It is necessary to change the dustpan to clean up the mulberry leaf residue and silkworm feces.
Take out the fresh mulberry leaves and spread them evenly in a clean winnowing basket, and spray one of them with a layer of brown sugar and garlic water.
Then pick up the mulberry leaf stalk with the larvae attached. The larvae are small, so you need to be careful and gentle.
It took a while to finish. The mulberry leaf residue and silkworm feces were roughly separated. The mulberry leaf residue was directly poured into the pit to ferment, and the silkworm feces were accumulated in a large wooden barrel.
A notebook and a charcoal pen are hung on the wooden rack, recording the time, dosage, and growth changes one by one.
When I got to the school building, the village school had already started classes.
Most of the girls are literate, knowledgeable in etiquette and skilled in housework.
After learning to read, some students practiced calligraphy, some practiced women's work, and occasionally chatted and laughed, making the schoolwork easy.
It is more difficult for boys. The Four Books and Five Classics must be read, studied and memorized. The imperial examination questions are taken from the Four Books and Five Classics, but what are derived from them are the strategies for governing the country and the world.
Even for the studies of law, calligraphy, and mathematics, one must be familiar with the Four Books and Five Classics; they are not completely unrelated.
Today is mathematics, Su Quanyan teaches how to calculate with counting rods.
Several complex math problems were written on the blackboard. The children used counting sticks to calculate and then wrote down their answers.
Su Ying took a glance and saw that it was addition and subtraction of two-digit and three-digit numbers.
The children were doing such a complicated calculation for the first time. They scratched their heads and put the counting chips on the table, horizontally and vertically, and their calculation speed was slow.
Children from Huanggou Village, such as Hu Zi, A Mu, Asang, and Bing Yan, are doing well. They have a good foundation and their speed is not fast, but their answers are correct.
Aniu and his gang of kids from Jinfeng Village had a hard time. Without any previous foundation, they only had a vague idea of how to do calculations with counting rods.
He took a small stick and swung it on the table, hitting people on the head.
There are five school buildings in total. Now with the addition of seven or eight children from Jinfengzhai, the classrooms can still accommodate them.
Aniu and his friends stayed in the large classroom and ate at the village vermicelli factory. The woman who cooked the vermicelli there also cooked for the children.
Abacus was a way of counting used by the ancients. Money and grain were all calculated through abacus operations. The "management" in "management of affairs" refers to abacus.
Use several sticks of the same thickness and size to place them.
For numbers one to five, place the corresponding number of counting sticks horizontally. For numbers six to nine, place one counting stick horizontally to represent five, and then place the counting sticks that are the difference from five below. Add up the total to get the number.
When expressing multi-digit numbers, use vertical format for the ones place, horizontal format for the tens place, vertical format for the hundreds place, horizontal format for the thousands place, and so on. Clear the number if zero is found.
This algorithm works fine for simple addition and subtraction, but it runs slower when it gets a little more complicated. It runs even slower when it comes to multiplication and division of multi-digit numbers.
Su Ying suddenly felt that instead of going through the trouble of learning counting rods, it would be better to skip learning how to use an abacus.
The abacus can perfectly solve the problem of multi-digit calculations using counting rods. It is a calculation tool invented when counting rods were used at a certain stage in ancient times to make calculations more complex and faster.
There are many theories about the origin of the abacus. Some believe it originated in the Eastern Han Dynasty and the Southern and Northern Dynasties, some believe it originated in the Tang and Song Dynasties, and some believe it originated in the middle of the Yuan Dynasty.
No matter which dynasty it originated from, Su Ying knew that it had definitely not been widely used at this time. There were confirmed records that it was widely used in the Ming Dynasty.
Zhu the shopkeeper came to receive the goods and fiddled with the counting sticks for a long time. Su Ying became impatient and figured it out using mental abacus.
When the goods were delivered later, Shopkeeper Zhu was too lazy to count. He saw Su Ying stretch out her left hand and mutter something like a Taoist priest, and quickly reported the number.
At that time, Su Ying didn't think about teaching abacus. She just wanted to settle the bill as soon as possible and didn't want a large group of people to wait.
Now, when the cousin asked the children to do a simple addition and subtraction of three-digit and two-digit numbers, they needed a handful of counting sticks and fiddled with them for a long time, but their speed was really slow.
Only then did I feel the need to teach abacus and cultivate a group of young calculation experts.
Thinking of this, Su Ying returned home, picked up a charcoal pen and drew an abacus on paper. There were seventeen pillars in a frame, each with seven beads, divided into two parts by a horizontal beam, two on the top and five on the bottom.
"Hey, Aying, what are you drawing again?" The three sisters-in-law finished their work and prepared to make lunch.
"Draw an abacus!" Su Ying marked the dimensions.
"Abacus? What's it used for?" The three sisters-in-law came over to take a look.
"It's a more convenient calculation tool than counting sticks. I just saw Brother Quan Yan teaching the children counting sticks, and he thought it was too troublesome." Su Ying explained.
"How do you use this abacus?" Yang Chunhua held up the blueprint. "One on it is five, and two on it is ten, right?"
"Hey, Second Aunt, how did you know?" Su Ying was surprised.
"Well, I've seen something similar in the Imperial Observatory when I was young. The Imperial Observatory's calculations of time and calendar are pretty much the same as yours." Yang Chunhua said.
“I just didn’t expect you to use it to settle accounts, but now that you put it, it makes sense.
The Imperial Astronomical Observatory's calculations of time and the calendar are quite complex and tedious, but they have to be used. Why hasn't anyone thought of using it for accounting? It's so convenient!
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