During the summer vacation, my parents and I went to my cousin's house to play. I was thirsty on the road, so my father had to buy mineral water from the nearby grocery store. There is a rule in the grocery store: if you buy three bottles of mineral water, you can get a bottle of mineral water, and the price of a bottle of mineral water is 1 yuan. When my father saw it, he took out 10 yuan and gave it to the grocery store owner, saying, "The boss bought 10 bottle of water." When I got the water, I drank it hungrily, and soon I drank two bottles. Before I came to my senses, there were several empty bottles. Dad asked me, "Lingling,1how many bottles of mineral water can 0 yuan exchange?" I think: I drank 10 bottle of water, 9 empty bottles were replaced with 3 bottles of mineral water, 3 empty bottles were replaced with 1 bottle of mineral water ... and there were two empty bottles left. I happily said to my father, "Dad, I have worked it out. Yes 14 bottle of mineral water, and there are 2 empty bottles left. " Dad smiled and said, "Think again!" I said thoughtfully, "We can borrow another empty bottle from the grocery store owner and return it to the boss after drinking it. Oh! We can drink 15 bottles of mineral water. " Dad nodded in praise.
Mathematics is to use it flexibly and integrate theory with practice. Only by mastering the knowledge of mathematics can mathematics serve us better. So we should learn mathematics well and make mathematics a good helper in our study and life.
I took 10 yuan to buy books on the third floor of Trust-Mart today.
I searched and found a book "Myths and Legends". When I saw the cover, I knew there were many wonderful stories in it. I decided to buy it, but when I saw the price, I was shocked again. It turns out that this book is 1 1 yuan. Feel the money in my pocket when reading this book. I'm really embarrassed!
The assistant aunt saw my embarrassment and asked kindly, "What's the matter, little friend?" I said shyly, "I want to buy this book, but I don't have enough money." She asked again, "How much money did you bring?" "Cai 10 yuan." I said. Aunt smiled and said, "Look at the price tag, kid. It says' Books are sold at a discount, with a 10% discount'." I asked, "What do you mean by' 10% discount'?" Aunt said: "It is to collect money at nine tenths of the pricing. For example, 10 yuan's books only accept 9 yuan."
I calculated that this book is only 9.90 yuan. "Yes!" I thank my aunt again and again.
I bought a satisfactory book today and learned knowledge. I'm so happy!
At noon today, I'm doing the math winter vacation homework of Grade Two and Grade Three in math diary Primary School. Unfortunately, I met a very difficult problem. I thought about it for a long time and didn't come up with one, so later. The problem is this: there is a cuboid, the product of the front and the upper two areas is 209 square centimeters, and the length, width and height are prime numbers. Find its volume.
I saw it and thought: this question is really difficult! We only know the area of two faces, and the volume must also know the length, width and height, but there is no hint at all. How does this start?
Just as I was scratching my head, my mother came. My mother first taught me to use the idea of equations to solve, but I am not very familiar with this method of equations. So, my mother taught me another method: first list the numbers and then exclude them one by one. First, we listed a lot of numbers according to the requirements of the topic, such as: 3, 5, 7, 1 1, and then we began to exclude them, and then we found that only1and 19 were left. At this time, I thought: one of these two numbers is the length of the common side of the front of the cuboid in the question; One is the front of the cuboid, divided by the sum of the lengths of other sides (both are prime numbers). So, I began to tell which number these two numbers were.
The final result is 374 cubic centimeters. My formula is: 209 =119 = 2+171× 2×17 = 374 (cubic centimeter).
I am happier than anyone to solve this problem. I also understand the truth that mathematics is full of mysteries, waiting for us to explore.
On the evening of the fourth grade in math diary Primary School, I saw a difficult problem in the Olympiad Book: the number of apple trees in the orchard is three times that of pear trees. Master Lao Wang fertilizes 50 apple trees and 20 pear trees every day. A few days later, all the pear trees were fertilized, but the remaining 80 apple trees were not fertilized. Excuse me: How many apple trees and pear trees are there in the orchard?
I am not intimidated by this question, but it can stimulate my interest. I think the apple tree is three times as big as the pear tree. If two kinds of trees are to be fertilized on the same day, Master Lao Wang will fertilize "20×3" apple trees and 20 pear trees every day. In fact, he only fertilizes 50 apple trees every day, which is 10, and the last 80 trees. Therefore, Master Lao Wang has been fertilizing for 8 days. 20 pear trees a day, 8 days is 160 pear trees. According to the first condition, there are 480 apple trees. This is to solve the problem with the idea of hypothesis, so I think the hypothesis method is really a good way to solve the problem.
Up to today, we have completed a set of math review papers for Grade Two and Grade Five in primary schools, and I have solved the problems one by one. When doing review papers at school, I also found some Olympic math problems to do after class.
There is a topic that I still remember very clearly-shopping in winter and winter. Suddenly a child wanted to make friends with her and asked her how old she was this year. Dongdong smiled and said, "My age plus 7, divided by 4, multiplied by 3 and subtracted by 2 is exactly 10. How old do you think I am? " Hearing this, the child couldn't answer.
As soon as I finished reading the topic, I arranged it into a formula according to the words of Dong Dong: {[(□+7) ÷ 4 ]× 3}-2 = 10, and then regarded the operation in {} as the minuend, and used 10+2 to get the operation result in {} as 65438+. After listening to my analysis, the teacher nodded and praised me: "Yu xx, how clever!" "
Math diary Grade 2 6 "Wow! I will have a Chinese math exam tomorrow. I am so nervous! " I opened my mouth and whispered. On second thought, a series of questions popped up in my mind: Is mathematics difficult? What is a Chinese composition? I scratched my head with my hand.
The exam is finally coming, and I am both nervous and excited. All of a sudden, it seems that several drums are playing drums, and all of a sudden, it seems that several elves are shouting: "Come on! Come on! " At this time, the naughty Khan doll "ran" into my hand.
The math test paper was handed out, and the classroom was silent. I glanced at the test paper and answered the questions in a hurry. It is true that there is a rustle in the classroom and the examination room is the battlefield. Look, aren't all the students fighting nervously?
I'm relieved to finish the test paper successfully, but it's still early. I took out a piece of draft paper and began to examine it carefully. Ah! When I write a wrong question, I quickly take out the eraser from the pencil box, erase the wrong question and write down the correct answer. I am lucky: "Fortunately, I checked carefully!" "
The math exam is over and the Chinese paper is distributed. First of all, I have a quick look at this composition, which is a sequel to the story. I think this is my specialty! I can't help but feel relieved!
I finished my previous topic at once. Finally, I wrote a composition. As I write, I think, the pen in my hand is like a dancing villain. I read the composition, which is quite interesting. My sweet, annoying and nervous aunt was also driven away.
Now, I finally understand the meaning of liberation!
These days, in the seventh grade of math diary Primary School, Mr. Qian taught us a simple algorithm of multiplication and division in order to let us work out the results of some questions faster. I thought to myself: I can calculate vertically quickly, too. Is there any other way to make calculation faster? I listened carefully to Mr. Qian's lecture with full questions, and finally understood the truth. It turns out that to simplify the operation, we must first understand the basis of multiplication and division. Multiplication is based on:
Multiply three numbers, you can multiply the last two numbers first, and then multiply the first number, and the result remains the same. The basis of division is that a number is divided by two numbers in a row, and when it is divisible every time, you can multiply the two numbers first, and then divide the numbers by their products, and the result remains the same.
Let me give you an example: 25× 16=25×4×4, = 100×4, =400. How's it going? If you calculate this formula vertically, it will take about one minute, but if you use a simple algorithm to do this formula, you can quickly calculate the result. Shortly after I learned simple calculation, my father gave me a question and I answered it immediately. I calculated it this way: 35× 12=35×2×6=70×6=420. My father listened to my answer and praised me. I'll tell you a little knowledge: it's best to find a number and multiply it to get a whole ten or a whole hundred.
Simple algorithm is easy!
Comments: "Applying what you have learned" is the pursuit of the new curriculum. The young author experienced the extensive application of mathematical knowledge with his own personal experience and felt the pleasure of success.
This morning, my mother and I went to buy breakfast.
When I arrived at the hotel, I asked my uncle, "How much is a fried dough stick? How much is a bag of soybean milk? " My uncle said kindly, "A fried dough stick costs fifty cents, and a bag of soybean milk costs fifty cents." At this time, my mother asked me a question: "A fried dough stick and a bag of soybean milk are fifty cents, so how much does it cost to buy five fried dough sticks and five bags of soybean milk?" At this time, I thought about it carefully. 5525, 2×25=50, equals 5 yuan. Mom added, "There is a simpler way. Think again! " "I patted my head, thought for a moment, and finally figured it out. I am happy to tell my mother: "1 root fried dough sticks and 1 bag of soybean milk need 1 yuan, and one fried dough sticks and a bag of soybean milk is 1 serving, so five portions are not 5 yuan money! My mother gave me a thumb and said, "Son, you are great! " "
Mathematics used to be so profound, so interesting and so important that we could apply a lot of knowledge from our daily life. We must learn math well, not only other math courses are also important.
In short, we must study hard and make progress every day!
I got a score of 100 in this math exam of Grade 9 in math diary Primary School! I still remember that I finished this paper with a nervous mood. After the first class, I found a blank piece of paper on the table, and I thought: No way! Is it that the exam is curly? I shivered and opened it. It turned out to be a big test paper, not an answer sheet. I felt a sort of surge of relief. At the beginning of the second class, I felt very uneasy, as if something was going to happen to me, but I was very uneasy all over. After class, I came to my desk and found another piece of white paper on my desk. "This is definitely another big exam." I casually opened a blank sheet of paper and saw that it was not a big test paper, but a real answer sheet with a "ham sausage" and "two eggs" staring at me! My nervous heart suddenly let go and became a happy heart. This is the first time in my life that I got full marks in math test. There used to be only a few points difference, so getting full marks in the exam became my dream, and it finally came true today. When I got home, I wanted to surprise my mother and cried and said to her, "Mom ... I didn't ... I didn't do well in the math exam ..." My mother asked anxiously, "How could I fail in the exam? Don't you usually work hard? " After that, I wiped my tears and suddenly changed my face and said, "Haha! Mom, you've been cheated! I got 100. Do you think your daughter is so stupid? " "alas! You little girl, your acting is good. When you grow up, you can be an actor! " Then we all laughed. Get up.