Math diary's composition

After a busy and fulfilling day, there must be a lot of feelings in my heart. Please write them down in my diary. Is it impossible to write without a clue? The following are six math diary compositions that I have carefully arranged for your reference, hoping to help friends in need.

Math diary Composition 1 My sister and I attended the Sunshine Youth Summer Camp. My mother gave me 200 yuan pocket money. Don't mention how happy you are. Finally, I can buy my own favorite things. As soon as I got on the train, I started a shopping spree: I bought a bottle of iced black tea and spent 10 yuan; A bag of peanuts spent again 10 yuan; A bag of cumin mutton skewers, 10 yuan; Three sets of playing cards cost 9 yuan money, one * * * cost 39 yuan money, and 200-39= 16 1 (yuan) left 16 1 yuan. As soon as I got off the train, I got on the bus to the Expo site. There are more than 200 national pavilions in the Expo site. We visited the USA Pavilion, pacific alliance Pavilion, Australian Pavilion, Indonesian Pavilion, Danish Pavilion, Petroleum Pavilion and Thailand Pavilion ... We only visited 22 national pavilions once, and the USA Pavilion and pacific alliance Pavilion left the deepest impression on me. The United States Pavilion has three pavilions, and the United Pacific Pavilion has 14 Pacific countries and two countries to participate, showing the beautiful and magical natural landscape, unique human environment and passionate folk customs of Pacific island countries to the people of the world.

Here I bought a Haibao key chain for my mother with 15 yuan. I spent 10 yuan to buy a Kongming fan for my father and 10 yuan to buy myself a bamboo sword. On the train back to Zhengzhou, I bought a massager for my father with 20 yuan money, a toy for my brother with 10 yuan, three boxes of fruit with 30 yuan money, a bag of food with 10 yuan, and the price was 39+ 15+20+ 10 × 4. After listening to my parents' analysis and teaching, I really feel a little extravagant, and some money really shouldn't be spent. This trip gave me a great education.

Math diary Composition 2 Today, my family went shopping in the supermarket. We first went to the kitchen counter and bought two fresh-keeping bags, one *** 16.8 yuan. My mother asked me 1 how much it costs. I couldn't help saying, "1 8.4 yuan." Then we went to the commodity counter, and we bought three large shoe polishes, one *** 15 yuan. Dad asked me how much is one? I said, "15 yuan divided by 3 equals 5 yuan." Then we went to the toilet paper counter. We bought three packs of toilet paper, 18 yuan. My brother asked me, "1 How much is the toilet paper?" I said confidently, "Six dollars." Then we went to the apple counter and bought 3 Jin of apples, each Jin of 4 yuan. My uncle asked me, "How much is a * * *?" I said without hesitation, "Yes 12 yuan." We finally came to the dental counter and bought two Yunnan Baiyao toothpaste and one from 28 yuan. My mother asked me, "How much are two?" I hesitated and said, "56 yuan."

It turns out that shopping also has math!

Math diary Composition 3 Today, the teacher will tell us about synthesis and practice.

When you open a book, the first thing you see is to estimate the number of nails in a pile. How to calculate this? I can't count it at all! Finally, according to the formula in the book and the teacher's explanation, I finally understood: first take out a small pile of nails and weigh them, then count how many nails there are, then weigh all the nails, and finally divide the two data to know how many nails there are. Moreover, the students also came up with another method: you can divide the nail into roughly the same number of pieces, count one at random, see how many pieces there are, and then multiply them, so that you can also work out how many pieces there are in a * * *.

Later, the teacher came with us to count the number of grains in half a cup of rice. We used a weighted balance. First, we put a gram of weight, and then put rice grains. The rice grains are about 100, and half a cup of rice grains are about 10g, so101×100 =1000 (grains Wow! I see!

When I got home, I also did something similar to nailing-counting red beans. First, I divided the red beans into three equal parts, and then counted about 822 red beans in each part, so 822×3=2466. Finally, after many checks, we finally got the result, about 2466. Returning to the classroom the next day, the teacher measured the number of red beans with a balance. My result is basically the same as the teacher's, and I am very happy. This shows that I have mastered the method and can solve the problem by myself.

After this comprehensive practice class, I learned a lot, such as how to estimate, how to calculate and so on. It's really rewarding for me.

Math diary Composition 4 Today, my mother and I went to the bookstore to buy books. I found a puzzle in a book called Interesting Mathematics. The problem is this: Bill spent 10 yuan bought a dog, sold it 15 yuan, then spent 20 yuan to buy it, and finally spent 25 yuan to sell it. Did Bill finally make money or lose money? I feel that I have bought and sold, sold and bought again and again, and my thinking has always been confused. I went to ask my mother, and she said, "If you can classify according to the number of' buying' and' selling', you will be suddenly enlightened. I think: the money used for "buying" is 10+20=30 (yuan). Money earned by "selling": 15+25=40 (yuan). Obviously Bill made money, earning 40-30= 10 yuan.

Comments: Students learn mathematics and apply what they have learned to real life, which can promote the formation of students' awareness of exploration and innovation. Through students' personal experience, students not only learned vivid mathematics, but also felt the existence of mathematics in life, and also experienced a happy and successful emotional experience.

On the way, we smelled a fragrance. It turned out to be a cake shop. So we agreed to buy a cake to eat together. "Boss, how much is this cake?" I pointed to a triangle cake and said. The boss replied, "One piece 1 yuan 50." My sister took 5 yuan money out of her pocket and gave it to her boss, who gave her 2 yuan 50 cents. At this time, I was surprised: this cake is 1 yuan.50, and my sister gave her boss 5 yuan money, but why did the boss only give her 2 yuan.50? I think: 5 yuan =50 angle, 1 yuan 5 angle = 15 angle, 50- 15 angle =35 (angle) =3 yuan 5 angle. Yes, the boss dialed the wrong number, so I told him, and the boss returned all the money to me. ...

(Comment: Mathematics comes from life and is closely related to human life. The little author used his knowledge of mathematics to solve a little thing he personally experienced in his life-"buying a cake" was cheated, realized the importance of learning mathematics, and had a strong thirst for knowledge of "I want to learn". )

I was doing an Olympic math reasoning problem this morning and was stumped by a problem. The title of this question is: In a theft case, the judge questioned four suspects A, B, C and D involved. A said, "The criminal is between B, C and D." B said, "C stole it." C said, "One of them is a criminal." Ding said, "B is telling the truth." After verification, two of the four people told the truth and two lied. Can you find the real criminal? I thought about it for a long time, but I still couldn't find the answer, so I had to ask my father.

Dad read the topic and said, "Of the four sentences, only two are true. You can't see them at once. You can assume that one sentence is true to reason." Therefore, this is the breakthrough to solve the problem. "

Encouraged by my father, I began to reason: "Suppose A is telling the truth, then one of B, C and D is telling the truth. If B is telling the truth, then D must be telling the truth, which makes all three people tell the truth and not meet the requirements. So, B is not telling the truth, so D is also telling lies, and C is telling the truth. So in this case, A is telling the truth.

Comments: The little author was stumped when he was doing the Olympic Games. Under the guidance of his father, he opened his mind, was good at analysis and reasoning, and easily solved the problem. After such intensive training, his abstract thinking ability and logical thinking ability will be improved rapidly, which will benefit him for life.

Mom bought 1.5 kg of water spinach, at 3 yuan per kg. Mom asked me to calculate how much * * * would cost? I pondered for a long time and said, "Five dollars and fifty cents!" "Wrong, you see aunt to buy food quickly and accurately. It should be 4.50 yuan.

I was not convinced, and my mother said, "Buy some more meat!" My mother came to uncle's meat stall and bought 1.2 Jin of meat. How much does it cost per kilogram in 22 yuan? This time, I am a good boy. Before I came to my senses, I found a pen and paper, but my uncle who sold meat had figured it out. 26 yuan Corner 4, I thought: Uncle must have put the computer at the bottom. But I looked everywhere, but I couldn't find the computer. I asked my mother curiously, "How can uncle count so fast?"

It turns out that the uncle who sells meat is calculated by heart and half method. 1 kg, 22 yuan, 0.2 kg is 4.40 yuan, and 22 yuan +4 yuan is 4 jiao, which is worthy of being 4 jiao of 26 yuan.

(Comments: This student is good at observing the problems in life, and is good at acquiring knowledge from life practice and applying it to life, so that knowledge will come alive, not just those digital games in books.

Today is Sunday. My mother got up early in the morning and bought a bag of eggs. She will teach me how to cook my favorite scrambled eggs. I picked up an egg and touched it in my hand. I found it very smooth. I put the egg on the table and observed it with my eyes. I found it to be a flat oval. Then I went to observe the corner of the egg. I found the edge of the egg, but I couldn't find a corner of it. At this moment, I thought: It turns out that eggs have no horns, because they are round. Actually, it's as round as an egg, and there are volleyball, football, basketball, table tennis ... Haha, I've learned a new math knowledge!

(Comment: There is mathematics everywhere in life, and the little author can also find mathematics in learning scrambled eggs. It can be seen that as long as you are a caring person, you can always find mathematics in real life. )

In this morning's math class, I learned a lot about the year, month and day. For example, there are 12 months in a year, including 7 big months and 4 small months. February is a special month, which we call a special month. I know the way to remember the month, that is, clench your left fist and count 1- 12 on it in turn. Every month, the convex place is 3 1 day, and the concave place is 30 days except February.

I also know that there are usually three normal years and one leap year every four years. Gregorian calendar years that are multiples of 4 are usually leap years. For example, 1988, 1992, 1996 and 20xx are all leap years. 20xx is a normal year, so February of 20xx has 28 days. However, the Gregorian calendar year is a whole hundred, and it must be a multiple of 400 to be considered as a leap year. For example, 1900 is not a leap year, but 20xx is.

I have one more question before class. Why are there 365 or 366 days in a year? Is there 30 days in a month or 3 1 day? There are 24 hours a day. In class, the teacher explained to us through the three-ball motion diagram, which made me understand that the earth rotates once a day, that is, 24 hours, the moon rotates around the earth for one month, and the earth rotates around the sun with the moon for one year.

(Comment: The author can sort out and record what he learned in a class after class, discover the mystery of mathematical knowledge, stimulate the fun of learning mathematics and arouse the desire to explore mathematical knowledge. Perhaps this is the beauty of remembering math diary. )

It was a rainy Tuesday in Mao Mao. I went to school with an umbrella and suddenly found the study garden on the first floor surrounded by many classmates. Curiosity immediately drove me to run over to see what was going on. Take a closer look, and with a "wow", there is a new topic in the wide angle of mathematics! No wonder it attracts so many students to see it! I got into the crowd and saw this question written on it:

A person wants to cross the river by boat. He only has a boat and three things: a chicken, a dog and a basket of vegetables. You can only take one thing across the river at a time. When people are not around, dogs eat chickens and chickens eat vegetables. How can I ensure that the three things I bring are intact?

I had a brainwave, and the answer was that dogs can't eat vegetables. They can send the chickens first and then send them back empty-handed. Considering that chickens can eat vegetables, bring them back, take the dogs and vegetables together instead, and finally bring them back. Yes, this is the answer. I smiled sweetly.

Comments: Mathematics wide angle often attracts the attention of many students with its novel way and interesting topics, which makes students "play" bad. The young author was first attracted by the "wide angle of mathematics", then "pondered" with his heart, and finally the answer naturally surfaced. I think this kind of stimulating study, active exploration and methods can be described as doing nothing but "reaching".

Writing a Chinese diary has long been a common practice for students. Math diary writes "Hehe", never heard of it! Let's take a look at how our class keeps a diary and uncover their "secrets" together. This semester, Teacher Zhang said, "From today on, I will write an article about math diary every week." "No way", the whole class cried out with one voice, opened their eyes wide and wondered what was going on. Why did math diary have to write? Teacher Zhang Zhang looked at our class with a surprised expression and said, "Don't take it amiss. Math diary just wants you to write out the whole process of what the teacher said in class today, and then think about why the teacher said so? " We nodded in confusion and went home.

The next day, as soon as "math diary" was handed in, Mr. Zhang smiled and said to us, "You see, some students listened carefully and couldn't remember. In desperation, they wrote down what they thought when they deserted, and there were many jokes. " After class, some students said, "There will be no more desertion in class, otherwise how can math diary finish it?" ? Keeping a diary is equivalent to reviewing. "It suddenly occurred to me that some people say that cows have two stomachs. The grass they eat during the day will be turned up and chewed at night. The same is true of math diary?

Comments: Cultivate students' inquiry consciousness and let students feel the charm of mathematics through observation, imagination, thinking and emotion. I believe that primary school students have great wisdom in writing about math diary. As long as they work hard, math diary will write more brilliantly.

When I came to the supermarket, I saw all kinds of colorful dolls: cute puppies, clever monkeys and naive pigs. I was moved at first sight and thought: My birthday presents are usually little dolls. How did my father become a book buyer today?

I came to the bookcase reluctantly. My father looked around and picked and picked. After a while, he picked out four books from the shelf-five thousand years up and down. I looked, wow! 76 yuan. I said, "Oh, it's too expensive. 76 divided by 4 equals 19. A book 19 yuan is more expensive than a doll. " Then I remembered the little doll I bought with my mother last time. One is 8 yuan, and 76 divided by 8 equals 9, so I can buy 9 dolls and leave 4 yuan. What a bargain! At this time, I said to my father, "It's so economical to buy dolls. Why buy books? " Dad smiled and said to me, "The knowledge of these four books is worth more in 76 yuan."

Mathematical knowledge comes from life and is used in life. The little author is good at observing the reality of life from the perspective of mathematics, applying what he has learned to life, solving practical problems in life, having a reasonable and correct consumption view since childhood, and realizing the real value of mathematics.

Tonight, I just finished my homework and have nothing to do. I said to my mother, "Mom, I have finished my homework. What should I do now? " Mom said, "Now, just buy me 3 Jin of apples!" " "I agreed. My mother gave me 10 yuan and said, "Buy another half catty! "I readily agreed, happily took the money to the fruit shop, picked three and a half pounds of fruit, and said to the salesman," Help me calculate. " Aunt said, "You can calculate first." I thought about it and said to my aunt, "Is it 3×3=9 (yuan), then 3 yuan ÷2= 1 yuan 50, and finally 9 yuan+1 yuan 50 =1yuan 50." I said, "no, aunt, I don't have enough money." I still need 50 cents. What should I do? " I thought about it and said, "then make up my pocket money!" I scraped in with pocket money. " Say to your aunt, "That's enough now." Aunt said, "You are so smart. You bought an apple with your wisdom! " "

(Comment: Learn math, use math. The little author can apply the mathematics knowledge learned in class to real life and deal with practical problems flexibly. That's great! )

Math diary Composition 5 met another math problem today, and I worked hard to solve it. The topic is: there are 30 birds in two trees, and 4 birds fly away from the second tree first. At this time, tree A flew to tree B with three birds, and the birds on the two trees were just equal. How many birds are there in each tree?

As soon as I saw the topic, I knew it was a reduction problem, so I solved it by the method of reduction problem. But when I checked, I found something was wrong. I will do it again more seriously. I think there are as many as four missing, half of them are 13, and the restored B-tree is14; A tree is 16. The formula is: (30-4) ÷ 2 = 13 (only); 13-3+4 =14 (only); 30- 14 = 16 (only). The answers are: a tree 16 and b tree 14.

By solving this problem, I understand that no matter what I do, I should be careful, otherwise, even if I master the solution to the problem, the result will be wrong.

It is sunny today. I was reading Mathematical Olympiad in Primary School at home, and suddenly I found such a problem: compare11111,1 165538. Suddenly, I became interested and took a pen and "brushed" it on the toilet paper. Soon, I found a solution Is to turn these two false scores into fractions and then use the law of fractions. The smaller the denominator, the greater the score. Solve11111111×165438. 1 1 1 1 1/ 1 1 1 1。

Math diary Composition 6 I saw a young man buy a meatball skewer on TV today, which cost five yuan each. The uncle who sells meatballs set the price of a bunch in 0.5 yuan. When he sold meatballs, he miscalculated his name and made money. He thought that the string of 1 money was only given to five young people. As soon as the young man calculated, he said to the meatball seller, "Your calculation is wrong. There should be 10 meatballs. The man didn't hear the change. The young man persuaded him and gave him 1 1 string. The young man said, "I am different if I have one more." If you take it, you have to be an honest and trustworthy person. I can't eat any more. It turned out that math helped me.

I used to, and today's things finally happened. My grandfather took me to the barber shop to wash my hair. The price of shampoo was once in 5 yuan. After washing, the owner of the barber shop was too busy because there were too many customers. My grandfather gave him 10 yuan, but he asked my grandfather for 7 yuan money. My grandfather left without looking at the money, halfway. My grandfather felt in his pocket and found more than 2 yuan's money. My grandfather took me home and went back to get it. "

In these two things, it is very important to be an honest and trustworthy person, and an honest person is blessed by God.

Fan Siwen

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