bookcurios Chapter 38 Chicken and Rabbit in the Same Cage
Chapter 38 Chicken and Rabbit in the Same Cage
During this Dragon Boat Festival, Lu Lingxi rested for five days. She didn't see Master Yan for five days and actually felt a little bit missed. The main reason was that apart from reading storybooks, she had no entertainment at all and no friends invited her out to play.
Xiao Yu'er's injury recovered quickly. Today was the first day of Lu Lingxi's class after the Dragon Boat Festival, and he came. Today he was no longer wearing all black, but a light blue suit, with a simple light blue headband on his head that matched his clothes, which made his skin look even whiter. He looked like a weak scholar, not like a secret guard at all.
Lu Lingxi was stunned when he saw Xiaoyuer coming in, like a banished immortal. Chunhong and Liulu stood behind him and looked at Lu Lingxi's stunned look. Liulu couldn't help but complain to Chunhong: "Look, what did I say? Young ladies are easily deceived by beauty. It's so rude to stare at others like this."
Chunhong quickly put her right index finger to her lips and made a gesture to silence Liulu, and Liulu stopped complaining about Lu Lingxi.
Lu Lingxi also came back to his senses from Liu Lu's complaints, turned his head away from Xiao Yu'er, and stuck out his tongue awkwardly. He said angrily in his heart: "You have nothing to do but dress up so fancy for class? You are not doing your job properly!"
Xiao Yu'er, who was dressed up in fancy clothes, was very satisfied with Lu Lingxi's reaction and Liu Lu's words. Her overly soft appearance inherited from her mother was still useful.
When Master Yan arrived, Xiao Yu'er and Lu Lingxi had already taken their seats. Master Yan looked at the handsome man next to Lu Lingxi and couldn't help but sigh that General Lu was really brave. Such a man dared to spend every day with Miss Lu, and he was not afraid that Miss Lu would be abducted.
"Are you Xiao Yuer, whom General Lu mentioned to come to study with?" Master Yan looked at Xiao Yuer and asked, his tone was stern as usual. Lu Yi did not tell Master Yan the true identity of Xiao Yuer, but only said that this was someone he planned to train well, and let him and Lu Lingxi learn from Master Yan together.
"Yes." Xiao Yuer stood up and answered neither humbly nor arrogantly.
"How are you doing in your studies now? What books have you read?" Master Yan wanted to find out Xiao Yuer's current level of knowledge so that he could better balance Lu Lingxi's academic progress with his own.
"Master, there is no need to disrupt the progress to accommodate me. Just continue explaining according to the previous Lingxi progress." Xiao Yuer answered confidently.
Master Yan looked Xiao Yuer up and down for a while, and seeing his confident and determined look, he stopped talking and started the class.
"Last time we said that after we come back, we will start teaching arithmetic. Do you remember, Lingxi?"
Lu Lingxi didn't say anything, but nodded to indicate that he still remembered.
Master Yan continued, "Today I will give you an interesting problem from Sun Zi's Mathematical Classic to see how well you can comprehend it. The book says, 'There are pheasants and rabbits in the same cage. There are thirty-five heads on top and ninety-four legs on the bottom. How many pheasants and rabbits are there?' You should think about it for a while and then give me your answer."
When Lu Lingxi heard the question, he thought, "I know how to do this. I knew how to do it when I was in elementary school."
于是快速提笔在纸上写下：“设雉有X只，兔有Y只，因为X+Y\u003d35,2X+4Y\u003d94；所以X\u003d35-Y;所以2(35-Y)+4Y\u003d94;所以70-2Y+4Y\u003d94;所以2Y\u003d24,Y\u003d12;所以X\u003d23。既雉23只，兔12只。”
When Master Yan asked Lu Lingxi and Xiao Yu'er for the answer, Lu Lingxi quickly gave the answer: "Twenty-three pheasants and twelve rabbits."
But when Master Yan asked Lu Lingxi how he solved it, Lu Lingxi was stumped. He hesitated for a long time but couldn't explain it clearly. It was not easy to express it in words, so he showed his draft to Master Yan.
Master Yan was also puzzled when he saw her draft. He couldn't understand what the mess of symbols written by Lu Lingxi meant. "This... Lingxi, what are these things you wrote? Why can't I understand any of them? I haven't seen your calligraphy for a few days and it has deteriorated so much? I can't recognize any of your words."
Lu Lingxi realized that something was wrong. Oops! How can I explain that I wrote English letters and Arabic numerals? It's strange to suddenly say that I know these. "Master Yan, these are some simple numbers for doing pen arithmetic. I made them up at random. Let me think about how I solved it just now. I will explain it to you later. Otherwise, let Xiaoyuer answer first."
At this time, Xiao Yu'er was also staring at the pile of things written by Lu Lingxi. What Lingxi wrote didn't seem to be the language of the Southern Expedition Dynasty, but rather the language created by some foreign countries. How could a lady like Lingxi know these? He was lost in thought, and suddenly heard Lu Lingxi mention him, so he came back to his senses and said slowly: "My answer is the same as Lingxi's. The solution is: put thirty-five heads on the top and ninety-four feet on the bottom. Half of the feet, you get forty-seven, subtract the number from the number, and then divide the number by three on top and four on the bottom, five on top and seven on the bottom, one on the bottom and three on top, two on the bottom and five on top, and you get it."
After listening to this, Master Yan couldn't help but praise Xiao Yu'er for his intelligence and clear thinking. However, Lu Lingxi was confused and frowned, and asked in confusion: "What do these 'upper placement', 'lower placement', 'upper three divided by lower four' mean? Why don't I understand?"
Master Yan looked at Lu Lingxi and became even more confused. "I don't understand how you figured it out?"
"Um...well...Master, can you please explain to me what this means first, and then I'll tell you my thoughts, okay? You are the elder, so you speak first." Lu Lingxi still had to think carefully and organize his words.
Master Yan saw that Lu Lingxi was willing to learn, so he explained, "The so-called "upper placement" and "lower placement" refer to placing the numbers on the abacus board in two rows, upper and lower. Put the number thirty-five on the first row of the abacus board, and the number ninety-four on the second row. Divide the number of legs by two, so that the first row is thirty-five and the second row is forty-seven. Use the smaller number of heads to subtract the larger number of half legs, forty minus thirty (upper three divided by lower four), seven minus five (upper five divided by lower seven). At this time, the lower row is twelve, and thirty-five minus twelve (lower divided by upper three, lower two divided by upper five) is twenty-three. At this time, the remaining abacus in the first row is the number of chickens, twenty-three, and the remaining abacus in the second row is the number of rabbits, twelve."
Lu Lingxi still didn't quite understand what 'upper three divided by lower four' meant, and could only roughly understand it. He finally figured out how to explain it, and when Master Yan finished speaking, he said, "Master, I understand, but I'm still not very good at this calculation. My idea for this question just now is that pheasants have two legs and rabbits have four legs. I will assume that there are no rabbits here, only pheasants. Ninety-four legs divided by two equals forty-seven. If they were all pheasants, there would be forty-seven heads, but now there are only thirty-five. Forty-seven minus thirty-five equals twelve, and twelve fewer heads equals twenty-four more legs. The extra legs must be from the rabbit, so if there are twelve rabbits, then there are twenty-three pheasants. Calculate twenty-three times two plus twelve times four, which is exactly ninety-four."
After listening to Lu Lingxi's explanation, Master Yan and Xiao Yu'er both felt that this made sense. Xiao Yu'er said appreciatively: "Lingxi's explanation also makes sense, but I don't know how this is related to the pile of words you just wrote?"
Lu Lingxi scratched his head with his hand, looking embarrassed. I don't know how to explain it. It's too difficult for me. Finally, he gritted his teeth and explained: "I just drew it casually when I was thinking about the problem just now. I don't know what these symbols mean. I just thought it through and wrote an answer."
Seeing Lu Lingxi's embarrassed look, Xiao Yuer didn't want to embarrass her any further. He couldn't bear to see her frowning. After all, with her family background and status, she couldn't be a spy from another country. Seeing her embarrassed look, she probably couldn't even lie, so how could she be a spy?
So Xiao Yuer took the initiative to change the subject and said to Master Yan: "Master, since we have all given the correct answer, let's stop here. Lingxi said she doesn't know how to use the abacus, why don't we learn how to use the abacus today?"
Although Master Yan was a little interested in the symbols that Lu Lingxi had just explained, it seemed that Lu Lingxi could not explain it clearly. He did not want to waste any more time, so he began to explain the rules of the application of the abacus.