Math diary's composition

The day passed quickly, and we all had a new view of people and things. Let's take action and keep a diary at once. What are the novelty and richness of diary writing? The following are six math diary compositions that I have carefully arranged. Welcome to share.

Math diary's composition 1 "Qiu Zi, go shopping with your mother!" i really do not want to go. I have to prepare for the postgraduate entrance examination, and there are still many books to read. But I don't trust my mother to go alone. Mom has obviously aged a lot since dad left home. Mother is walking on the mountain road with a basket on her back. The air in the twelfth lunar month is full of fragrance, which is the smell of bacon, sausage and dried bean curd. It takes more than an hour to walk from the old Laoshan where we live to Xiangchang.

At rush hour, people gather from all directions to buy goods. Several years ago, the countryside was crowded and noisy. New year's goods eat the most, followed by clothes. What farmers produce is generally only enough for their own consumption and rarely sold. In addition, the transportation is convenient now, most of the rural dishes are shipped from other places, and there are many out-of-season vegetables.

Walking through the crowd, I asked, "Mom, what new year's goods shall we buy?" Jiaozi uses brown sugar; Vermicelli for stewing pig's trotters; There are also mushrooms and kelp, which are inseparable every year. I also need to buy some chicken essence, pepper, sesame oil, onion, ginger, garlic, pepper and pepper. You don't have to buy it if you have it at home. There is no shortage of side dishes, and tofu has been ground. "Mom has always been frugal. My tuition fees for studying mainly depend on student loans, and my mother earned the living expenses. If it weren't for her four pigs, two sheep, a cow and three acres of dahongpao oranges, I couldn't afford to read at all. I want to find a job early, but my mother insists that I go to graduate school.

Thinking of this, I hate my father again. He used to be a bricklayer, earning several hundred dollars a day, and his family life was relatively easy. But when he went to work in other places, he had an affair and wanted to divorce his mother. Mother refused, so he left and never heard from again. "It's almost noon. I have to hurry home after shopping, and I have to spend money on lunch in the street." My mother kept looking from one house to another while nagging, and finally stopped at a booth. That booth sells calendars, fortune-telling books and the like, and the quality is average. Mother picked up a calendar and asked, "How much is it?" "One Piece." Mom gave the money and left.

On the way home, I asked my mother why she bought a calendar. I can tell the date by watching TV. Mom smiled and said, "You must have a lunar calendar at home, so you will know what wheat to plant now, what awn to plant, and what jobs Grain Rain and the vernal equinox have. Your father used to remember this, but now that he is gone, I must remember that as you sow, you reap. "

Math diary Composition 2 Today, I played darts with my sister. I found many math problems from this game!

There are five circles on the dart target, the innermost circle is a red heart, and shooting can get 10 points, the second circle 8 points, the third circle 5 points, the fourth circle 3 points, and the outermost circle 1 minute. My sister and I had a life-and-death contest.

Sister, she scored 3 points on the fourth lap for the first time. The second shot dropped, and she didn't score! Just as I was smiling from ear to ear, my sister suddenly made progress. Hit the key and get 10 points. I am not happy now. Sister, she got a total of 13 points!

It's my turn I aimed for a long time. On the third lap for the first time, I scored 5 points. The second shot was not very good, only 3 points. If I want to surpass my sister, I have to shoot the innermost heart for the second or third time. As a result, I shot the second lap for the last time and won. I'm so happy!

Math diary Composition 3 Today, people can use positive numbers and negative numbers to represent two quantities with opposite meanings. For example, 0℃ is expressed as freezing point temperature, the temperature of boiling water is+100℃, and-10℃ is marked as-10℃. If the sea level is zero, the height of Mount Everest is about+8,848 meters, and the deepest Mariana Trench is about-1 1034 meters deep. In daily life, people often use "+"to indicate income and "-"to indicate expenditure. However, in history, the introduction of negative numbers has gone through a long and tortuous road.

The ancients encountered some problems in practice: if two people borrowed things from each other, the same thing had different meanings to lenders and borrowers; For another example, starting from the same place, two people walk in the opposite direction at the same time, even if the distance from the starting point is the same, but the meaning is different. Over time, the ancients realized that it is not comprehensive to express a thing only by quantity, and it seems that symbols indicating direction should be added. Therefore, in order to express quantities with opposite meanings and solve the problem that the minuend is less than the minuend, negative numbers are gradually generated.

China is the first country in the world to use the concept of negative numbers. Negative numbers have always been used in Nine Chapters of Arithmetic, clearly pointing out that "selling" is positive and "buying" is negative; "More money" is positive and "less money" is negative. Liu Hui annotated "Nine Chapters Arithmetic", defined positive and negative numbers as "the gains and losses of two calculations are opposite", and stipulated the addition and subtraction rules of rational numbers. He thought that "the theory of positive and negative operation: the same name benefits each other, and different names divide each other." These homonyms, namely, the same number, different numbers, division and benefit, are subtraction and addition. These ideas did not appear in the west until China in 8900.

India did not adopt negative numbers until the 7th century. In 628, India's Brahma System interpreted negative numbers as liabilities and losses. In the west, it was not until 1484 that Schuquet of France gave the negative root of quadratic equation. 1544, Steffi of Germany defined a negative number as a number smaller than any number. 1545, Italian Cardan wrote Dafa, which became the first book about negative numbers in Europe. Although negative numbers have already appeared in people's calculation process, they have not been recognized by academic circles for a long time. Until the17th century, mathematics, mechanics and astronomy were widely developed, and the use of negative numbers could greatly simplify the calculation, so negative numbers officially entered mathematics. Especially in 1637, the French mathematician Descartes invented analytic geometry, established coordinate points, and corresponded plane points with real numbers composed of negative numbers, zero numbers and positive numbers, so that negative numbers were explained, thus accelerating people's understanding of negative numbers. However, it was not until the19th century that the German mathematician Wilstrass and others laid a logical foundation for integers, and negative numbers gained a solid position in modern mathematics.

The fourth article of math diary's composition, "Rinrin Bell ……", is ringing, which is a math class. The students sat quietly in their seats, waiting for Mr. Fu to give us a lesson. Who knows, we are waiting for the fifth unit exam.

After a while, Mr. Fu came into the classroom with a dozen papers in his hand. After arriving at the podium, she said loudly, "Today we will learn Unit 5!" " "At the same time, some students sighed, and some students were very happy, as if they had won their fists. I thought to myself, "Although this unit is very difficult, I have reviewed it and I still understand the main knowledge points. This exam should not be difficult for me. Come on! Come on! Try to get good grades in the exam. "At this time, the test paper came into my hands, and I immediately picked up the pen and worked hard on each topic with an extremely high spirit. I solved all the previous problems one by one, and suddenly, a "roadblock" stood in front of me and wouldn't let me pass. This "roadblock" is so powerful that I am anxious like an ant on hot bricks. At this time, my mind was blank and I couldn't figure out how to solve the problem. I thought to myself, "I can fall into the pit this time!" "A topic will deduct a lot of points!" After thinking for a long time, I couldn't figure it out, so I just wrote an answer. I continue the following topic.

In the afternoon, the scores came out, and Mr. Fu asked the monitor Lei Zhihao to hand out the test papers. When he called my name, I was very excited and thought, "How many points did I get in the exam? God bless me, I must get more than 90 points, otherwise, I will see you again! " I stepped forward and picked up the test paper. Ah! 94 points, very happy to see the score.

Passing this exam made me understand that you can't eat hot tofu if you are impatient. As long as you study harder, you will get good grades!

Math diary Composition 5 Yesterday, the Menstrual family came back with a tour group. This is an active meeting. Mom, the last math problem is coming. It's menstruation.

Menstruation said, "When we went, it was the tourist season, and all the people in a big tour group stayed in hotels in the tourist area. However, there are not enough people and rooms. In order to let all tourists live in the guest room, even if there are 3 people in each room, 36 people have no beds; There are 4 people in each room, so 13 people have no beds. Obviously, I ask you, if there are five people in each room, how many beds will be vacant? "

I thought about it, and this problem is very similar to the "win-win" problem in profit and loss problem. If you want to calculate the number of rooms, apply this formula: "(big profit-small profit) ÷ every difference = number of copies" to calculate. I began to calculate: (36- 13) ÷ (4-3) = 23 (pieces)

23× 3+36 = 105 (person)

105 ÷ 5 = 2 1 (pieces)

23-2 1 = 2 (piece)

2× 5 = 10 (piece)

Oh! It turned out that 10 beds could be vacated!

Menstruation smiled and nodded, then said, "I'll ask you again." Our small team includes 50 tour guides. Now the tour guide wants to buy a bottle of water for everyone. She found that there was a promotion in the store, and it was stipulated that every five empty bottles could be exchanged for 1 bottle of water. How many bottles of water will she buy? "

Let me see: replacing five empty bottles with 1 bottle means buying four bottles and drinking five bottles.

50÷5= 10

10× 4 = 40 (bottle)

It seems that only 40 bottles are enough.

I couldn't wait to tell Menstruation the answer, and both Menstruation and his mother laughed. Mom said, "How about asking you to go shopping with your sister Kexin tomorrow?"

"oh! Great! " My sister Kexin and I cheer together.

"Sister, you are great!" Dear sister said. I was filled with joy and hugged her tightly.

There is mathematics everywhere in life, and you can't miss it.

Math diary Composition 6 This evening, my mother, my aunt and I came to Bai Jie for shopping. My aunt learned that I studied well and decided to give me a test. At a brand sale, Xiao Yan chose a coat with a price of 2258 yuan and a 30% discount. Mom picked out a pair of pants, the price is 858 yuan, and the same is 30% off. Mom, they hesitate to buy or not. When the salesman saw it, he said that both of them could be discounted by 2.5%, and the shopping mall would make a one-time payment after the discount from 500 yuan to 50 yuan.

At this time, my aunt gave me the first question and asked me to find a way to buy it cheaply. At present, there are two schemes, one is a one-time payment with a 2.5% discount; One is to pay separately. I chose the second one without hesitation, and suggested that my aunt's coat be cheaper first. But my aunt smiled at me mysteriously and said, "Really? Then forget it. " I checked it repeatedly on paper and found that the first scheme was much cheaper than the second one. I asked, "Aunt, how did you come to a conclusion in such a short time?" Xiao Yan said: "Just multiply the sum of the discount prices of two clothes by the difference of 3 fold and 2.5 fold, and then compare it with 50." Yes! Why didn't I think of that!

Aunt then tested me and asked me to calculate how much cheaper the first plan was than the original price. It's simple. I subtracted these two figures and quickly worked out: "2337 yuan!" " "This time is finally right!" Xiao Yan said.

I benefited a lot from this shopping. In addition to the material gains, the spirit has also been supplemented.

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