I used to think that learning the knowledge of "finding the least common multiple" was boring, and it was really annoying to deal with the problem of "finding the least common multiple of 1 1 2" all day. I have always felt that it is useless to learn this knowledge in my life. However, one thing changed my view. That was not long ago. Grandpa and I went to the Youth Palace by bus. My father and I took the No.3 bus and were about to leave when the 1 bus just took us away. At this moment, grandpa looked at two cars and suddenly smiled and said to me, "Xiao Ying, grandpa has a question to test you, okay?" "I answered with confidence," OK! " "That you listen up, if the 1 bus runs every 3 minutes, then the No.3 bus runs every 5 minutes. How many minutes will it take for these two cars to start at the same time? " After a pause, I said, "Grandpa, you can't solve this problem. "Grandpa looked at me doubtfully." Really? There is still one condition missing in this problem: 1 bus and bus No.3 start at the same place. Grandpa listened to my words, suddenly patted his clever bald head and said with a smile, "I, a doctor of mathematics, sometimes get confused, and I don't do the questions rigorously enough, but I still think carefully." "Grandpa and I smiled happily. Then grandpa said, "OK, now suppose it's the same starting point. How do you solve it? " "I thought about it and blurted out," 15 minutes. Because 3 and 5 are prime numbers, finding the least common multiple of prime numbers is equal to the product of these two numbers (3х5= 15), so 15 is their least common multiple. In other words, two cars can leave at the same time in at least 15 minutes. " Grandpa praised me: "correct answer!" 100 points. " "Yes!" After listening to grandpa's words, I raised my hand happily. From this incident, I understand a truth: mathematical knowledge is really everywhere in real life.

The results of the math contest were announced today. I got 98 points in the competition, usually ranked second or third. After I got the news, I thought happily, "Haha, this is my first place! By the way, tell mom the news and make her happy! "

So, with joy, I walked home at a brisk pace and told my mother the good news. My mother praised me a few words at first, and suddenly changed her tone and said to me, "Don't be too happy. As far as I know, there are people who do better than you! " After listening to my mother's words, I can't help but feel a little lost: after all, the first position is gone. But I can't help asking, "Huh? who is it? How many points did he get? " Mother smiled and said, "I don't know who it is." I only know his age, grades and ranking multiplied by 2574. Think slowly! " "

I don't think so. It's just a topic, but I can't beat this math high flyers! I wanted to think, went back to my room and thought:

Decomposition factor of 2574: 2574 = 3× 3×1/kloc-0 /×13× 2. This 2 is definitely a ranking, so it is the second place. If you are 9 years old, then the score is 143, which is wrong. It can only be age 13 with a score of 99! Ha! After calculation, the answer is ranking 2, age 13, and the score is 99!

After I worked out the answer, I hurried to tell my mother. My mother hugged me happily and said, "My day is great!" " "Now, I'm in a fog. It took me a long time to realize that my mother was lying to me, and I really got the first place in the exam. Just now, my mother tried to test my math ability and gave me a difficult problem.

In recognition of me, my mother decided to make a celebration dinner. I haven't had a toothache for a long time. After listening to my mother's words, I seemed to see the delicious roast duck and the delicious braised pork. I was so happy that I kissed my mother on the face and cheered again and again: "Thanks for math, long live my mother!" " "

About "0"

0, can be said to be the earliest human contact number. Our ancestors only knew nothing and existence at first, and none of them was 0, so 0 isn't it? I remember the primary school teacher once said, "Any number minus itself is equal to 0, and 0 means there is no number." This statement is obviously incorrect. As we all know, 0 degrees Celsius on the thermometer indicates the freezing point of water (that is, the temperature of ice-water mixture at standard atmospheric pressure), where 0 is the distinguishing point between solid and liquid water. Moreover, in Chinese characters, 0 means more as zero, such as: 1) fragmentary; A small part. 2) The quantity is not enough for a certain unit ... At this point, we know that "no quantity is 0, but 0 not only means no quantity, but also means the difference between solid and liquid water, and so on."

"Any number divided by 0 is meaningless." This is a "conclusion" about 0 that teachers from primary school to middle school are still talking about. At that time, division (primary school) was to divide a copy into several parts and figure out how many there were in each part. A whole cannot be divided into 0 parts, which is "meaningless". Later, I learned that 0 in a/0 can represent a variable with zero as the limit (the absolute value of a variable is always smaller than an arbitrarily small positive number in the process of change) and should be equal to infinity (the absolute value of a variable is always larger than an arbitrarily large positive number in the process of change). From this, another theorem about 0 is obtained: "A variable whose limit is zero is called infinitesimal".

"Room 203 105 in 2003", although all of them are zeros, they are roughly similar in appearance; They have different meanings. 0 indicator vacancy of 105 and 2003 cannot be deleted. 0 in Room 203 separates "Building (2)" from "House Number". (3) "(that is, Room 8 on the second floor) can be deleted. 0 also means that ...

Einstein once said: "I always think it is absurd to explore the meaning and purpose of a person or all living things." I want to study all the numbers of "existence", so I'd better know the number of "non-existence" first, so as not to become what Einstein called "absurd". As a middle school student, my ability is limited after all, and my understanding of 0 is not thorough enough. In the future, I hope (including action) to find "my new continent" in the "ocean of knowledge".