Math diary's composition

The day is coming to an end. I believe you will learn a lot. Let's keep a diary together. So do you really know how to keep a diary? The following is math diary's composition that I helped you organize. I hope it will help you.

Math diary Composition 1 Today is the 28th day of the second day of the Lunar New Year, and the weather is fine. My mother took me to the morning market in Baogong Lake to buy food. I jumped out of bed happily, dressed quickly and went to the market with my mother. Wow! The vegetable market is really lively, full of people, talking and laughing. I think it may be because it is faster than the Spring Festival. I saw round and red tomatoes like apples, long and thin bean sprouts, purple eggplant like a curved moon and a lovely boat, and many green leafy vegetables, such as lettuce, vegetables and cabbage.

Listening to my mother said, "On the first day of the New Year, my uncle, my second uncle and my aunt will come to my house to see my grandmother and spend the New Year with us." So my mother and I bought a lot of vegetables, such as: I bought two Jin of tomatoes and two yuan of A Jin; Wax gourd bought three Jin, one yuan A Jin; Long beans bought three Jin, two yuan per Jin; I bought two Jin of bean sprouts, one yuan per Jin. At this moment, my mother asked me a question. Xinxin, use your math knowledge to calculate how much it will cost to buy food today. I smiled and told my mother that a * * * costs fifteen dollars. The formula is as follows:

(22) (31) (32) (21) =15 yuan.

Math diary Composition 2 This morning, I swam home, and my father said, "Let's play a math game!"

Dad said to me, "You have learned the knowledge of clocks, so play a game of clock knowledge." The rules of the game are as follows: Xiao Fang's clock strikes every half hour except what time it strikes. For example: knock at 0: 30, 1: 00, 1: 30, knock at 2: 00, knock at 2: 30 ... At this rate, from 0: 00 pm to noon 12 during this 12 hour, the clock will * *.

My first calculation, carelessness made it 9 1.

I made a second calculation, and I did this: if the whole hour is removed, there are twelve in half an hour, which adds up to12; From one to ten, the method of ten is used. One plus nine equals ten, two plus eight equals ten ... equals 55, which is Gauss's law. 55+ 12+ 1 1+ 12=90。 I calculated that I would knock on the door 90 times. By the way, I am very happy!

There is also mathematics in daily life, and I think mathematics is very interesting.

Math diary Composition 3 Up to today, we have finished a set of math review papers, and I have solved all 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 Composition 4 Today we learned the first content of parallelogram unit-vertical and parallel. We learned a lot of useful little knowledge. I combined "it" into a short paragraph: two straight lines that do not intersect on the same plane are called "parallel lines" or "parallel to each other".

If two straight lines intersect at right angles, they can be said to be "perpendicular to each other", one of which is called the perpendicular of the other, and the intersection of these two straight lines is called the perpendicular. In class, the teacher also asked our group to discuss a question: which line segment is the shortest? After a few words, we finally came to a conclusion: the vertical line segment drawn from a point outside the straight line is the shortest. Later, we also learned how to draw parallel lines from the teacher; To draw parallel lines, you only need to draw with a triangular ruler and a ruler.

Draw several lines perpendicular to the parallel lines between two parallel lines. I measured the length of these lines with a ruler and was surprised to find that the distance between the two parallel lines was equal. This is my math diary! ~

Math diary Composition 5 This afternoon, my parents will take me to the seaside to catch crabs. We came to the seaside with a small bucket and two small shovels. Seeing the small hole in the beach, my father said, "This is a crab hole. Start acting now! " "

Mom dug with a shovel, or dad was the bravest and dug directly with his hands. I catch crabs on the beach. There are two big pliers in front of the crab. Only by grasping its shell will it not be caught. After a while, we caught many crabs. I caught nine little crabs, and my father asked me, "How many legs do nine crabs have?" I said, "7 2 legs! 8× 9 = 7 2 (strips). " My mother asked me again, "Dad catches three times as many crabs as you do. How many did dad catch? " I said, "Seven! 3× 9 = 2 7 (only). " Dad asked me again, "How many division formulas can you name with the formula you just used?" I thought about it and said, "I can also write two formulas separately." I wrote on the beach with a stick:

7 2 ÷ 8 = 9 ,7 2 ÷ 9 = 8 ; 2 7 ÷ 9 = 3 ,2 7 ÷ 3 = 9。

My parents praised me for my good study.

It turns out that learning math is good, and it can solve so many problems!

Math diary Composition 6 65438+1It was cloudy on Wednesday, October 20th.

misunderstand

In the fourth grade, there was a problem called "wrong solution". Let me give you an example: When Wang Chen used the remainder to calculate the division, he misspelled the dividend 17 1 7, and the quotient was 2 less than the original, but the remainder was exactly the same. What are the correct divisors and remainders?

This problem is actually very simple: 17 1 misspelled as 1 17, and the quotient is 2 less than the original, then the difference between1-17 is the divisor. Now that the divisor is found, it is simple. The topic says that the remainder is the same, and I divide the wrong dividend and the correct dividend by divisor. If the remainder is the same and the difference between the two quotients is 2, then the topic is done correctly. Formula: (171-117) ÷ 2 = 27; 17 1÷27=6……9; 1 17÷27=4……9; 6-4=2。 The remainder is the same, and the difference between the two quotients is also 2. A: The correct divisor is 27 and the remainder is 9.

Wrong solution is really fun!

Math diary Composition 7 It will be sunny on Friday, August 8th.

At 8: 08 tonight, the Olympic Games began. When countries entered the "Bird's Nest", my mother picked up a piece of paper and gave me a question. At the end of the ceremony, my mother wrote it. I took a look. It turned out to be the problem of area graphics that I am not good at. The topic is that a big square has 9 squares, and each square has 9 small squares. The area of a small square is 0.5*3.8 square centimeters. Q: What is the area of this big square? Answer time: 10 minute.

After reading the topic, I quickly calculated it. 0.5*3.8? The teacher didn't teach him. He worked it out by himself. 0.5 was expanded by 10 times and became 5; 3.8 magnification 10 times to 38. 5*38/ 100= 1.9; 1.9 * 9 = 153.9 (square centimeter) Just then, 10 minutes passed, and my father came over from the study and asked for the result. I answered truthfully: "The answer to this question is 1.9 * 9 = 153.9. Mom nodded, smiled and gave me a good score of 89 points, which is a good score I have never had before!

Today's 89 points make me so happy!

Math diary Composition 8 Today, I waited patiently for my father to buy wine at the gate of the community. Suddenly, the security guard spoke and said, "Little friend, it's Arbor Day soon. We may plant trees in Haiqinyuan Community. May I ask you a question? " I was shocked at that time, and the security guard wanted to ask me questions! Uncle Security then asked me, "We want to plant 18 trees, both sides. How many trees should we plant on each side? " I quickly replied: "9 trees." Hearing this, the security guard happily said to me, "Little friend, you are so smart!" " "

After a while, my father came back and the security guard gave me a big compliment in front of my father. I was flattered to hear that.

Oh, so this is the division taught by Teacher Zhang! I can also do formulas.

18÷2=9 (tree)

Math diary composition 9 I am full of joy, because I will have enough fun with my three sisters in Jinhua! Just then, the bus came! I quickly ran into the car and grabbed a seat to sit down! "Selling tickets! Tickets are on sale. " A crisp cry rushed into my ears, and an amiable aunt came up to me step by step. I took out my money and said, "Four people paid together to go to Zhejiang Middle School to buy books!" I don't know if my aunt is wrong! Or what? I only took the money from 8 yuan! And after receiving the money, he turned and left! So, I shouted: "Aunt, you took two yuan less!" " Aunt, turn around at once! I saw him coming up to me with a shy face and saying, "Little girl, I haven't miscalculated the money several times all year round. It's rare. I won't tell you if I do it several times!" " You are the first to tell me! "Say that finish, she took two dollars from me again, and boasted," Little girl, you! Really honest! " After saying what she said, my heart was filled with joy!

It seems that the decimal multiplication I learned is still very useful in our life! Of course, we should be honest!

Math diary Composition 10 It was a drizzly Tuesday. 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 and find out. 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?

After reading the topic, I thought about it. ...

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.

It's nice to have a wide angle in mathematics. I will definitely come here often in the future.

Math diary's composition 1 1 Mathematics is everywhere, and there is a lot of mathematics around. Mathematics is essential, otherwise it will bring all kinds of inconvenience to life. Let's look for mathematics and explore mathematics together.

"Circle" can be seen everywhere. Isn't the bottom of the moon cake box, teapot and medicine box round? But they are called cylinders as a whole. When you pick up these cylinders, you may think, why do you want to make the bottom round? Why not make it rectangular or square? I questioned this before, and now I can help you solve it!

When you make a cuboid, cube or cylinder with the same material, calculate the volume. We will find that the cylinder is the largest, the cube is the second largest and the cuboid is the smallest. I just realized that in order to save materials, I made these boxes round and increased their size.

This is the advantage of the cylinder.

Math diary Composition 12 At noon today, I was at home reading a map of China. My father asked me, "Do you know which railway to take from Beijing to Shanghai?" I replied, "Take the Beijing-Shanghai line." Dad asked again, "Do you know how many kilometers there are on the Beijing-Shanghai line?" Can it be measured by map? "

Looking at the winding lines on the map, I am a little confused. How to measure them? I tried it with a ruler first, but no, the bending place is not easy to calculate; I used the rope again, it was too thick, and it was not allowed. At this time, I saw my mother sewing clothes, so I used cotton thread and I measured it with my father. First, put the cotton thread along the beijing-shanghai railway line, cut off the redundant part, and measure the length of this cotton thread with a ruler as 15cm. Dad said, "What is the scale of the map we want to see at this time? I looked at it and it was 1: 9000000 ". According to this ratio, I calculated that the length of the Beijing-Shanghai line is 1350km, in order to test our measurement. I asked my father, why are the two sets of data different? Dad said, "We have measured it accurately, and it is normal to have a little error. After all, we measured it on the map with cotton thread. "

Math diary composition 13 I am filled with joy, because I will have enough fun with my three sisters in Jinhua! Just then, the bus came! I quickly ran into the car and grabbed a seat to sit down! "Selling tickets! The tickets are sold. " A crisp cry rushed into my ears, and an amiable aunt came up to me step by step. I took out my money and said, "Four people paid together to go to Zhejiang Middle School to buy books!" "I don't know is aunt is wrong! Or what? I only took the money from 8 yuan! And after receiving the money, he turned and left! So, I shouted: "Aunt, you took two yuan less! "Aunt immediately turned around! I saw him coming up to me with a shy face and saying, "Little girl, I haven't miscalculated the money several times all the year round. It's rare. I won't tell you if I do it several times!" "You are the first to tell me!" After that, she took two more dollars from me and boasted, "Little girl, you! Really honest! " After what she said, my heart was filled with joy!

It seems that the decimal multiplication I learned is still very useful in our life! Of course, we should be honest!

Math diary Composition 14 We had a mid-term exam a few days ago. I got 96 points in the math exam. Although it is a high score, I am not happy. Because it's a pity that I lost four points and I made some mistakes that I shouldn't have made.

However, I am not the kind of person who will be easily knocked down by difficulties! So, I began to analyze the reasons for losing points. After a while, I found three reasons: 1, I didn't review carefully before the exam. 2. I was too careless in the exam. 3. Math problems are not thought deeply.

One of the most regrettable mistakes is a judgment question. The topic is: there can't be rectangles in six faces of a cube. At that time, I thought of the sentence that a square is a special rectangle, so I made a mistake on this issue. Facts have proved that I was wrong, and this question should be correct.

There is another problem, which is also a true or false problem, that is, put 3 grams of salt into 100 grams of water, and the salt accounts for 3/ 100 of the salt water. Obviously this is wrong, but I am right. I haven't thought it over. After 3g of salt is put into100g of water, the total amount should be 103. It should be correct that salt accounts for 3/3 of 103 brine.

The exam has passed, so I should learn from it. I have made up my mind to get rid of all the bad habits. There is no best, only better!

Math diary's composition 15 often encounters some mathematical problems in life, such as buying food, shopping and trading. We can use the methods we have learned to solve mathematical problems to solve various mathematical problems in life.

Today, when we ordered take-out, the waiter told us on the phone that the price of goods had been adjusted a few days ago, so the price of goods had all increased.

Dad ordered the original price 12 yuan of "The Story of a Piece", but the current price is 15 yuan because of the price adjustment. How much is the current price higher than the original price? Subtract the difference of 12 from 15 and divide it by 12, (15-12) ÷12 = 0.25 = 25%. The original price of "Big Pai Rice" ordered by my mother is 10 yuan, and after the price increase, it is 12 yuan. So how much is the current price higher than the original price? 12 minus 1 1 is divided by 1 1, (12-10) ÷10 = 0.2 = 20. Based on the original price, the total price of the two meals is 12+ 10=22 (yuan), and the current price is 15+ 12=27 (yuan). What percentage is the current price higher than the original price? Subtract the difference of 22 from 27 and divide it by 22, (27-22)÷22≈0.227=22.7%.

Have you found the math problem of the price increase in this small restaurant?

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