Math diary, a pupil, has 500 words.
After lunch at noon, I had nothing to do, so I picked up a book called "Top Student Question Bank". Open the chapter on negative numbers, read the previous explanation, and turn to the exercise section to do exercises. I watched the exercises first. Although there is a lot of content, it is easy. I thought, "Hey! This is also called "top student question bank". It's so simple that I can do it with my eyes closed. "So, I started to do the questions, fill in the blanks, and judge the questions. I made two pages in a short time. Speaking of application problems, I thought it would be more difficult, so I read it carefully. This is not difficult at all. After two or three strokes, only one application problem was written. I have a cursory look at the problem. It's simple. No, it's accelerated. What are these "+15" and "-15" for? I'll think about it. I just can't answer the question. I read the question again, but I still can't. At this time, I thought of a formula I saw in a book, which seemed to be just right for this problem. I quickly turned out all the reference books on mathematics I bought, and read and reread them. Why not? I clearly saw this formula in the book, how could I not find it? Facts are facts, so I flipped through the back answer: 200 ÷ (35+15)+200 ÷ (35-15) =14 hours. Why divide 200 by 35? At this time, in the question of travel, I picked up the book "General Review of Primary School Graduation" and turned to the page about travel. There is a formula that makes me suddenly realize that it is like this: distance divided by speed equals time, and these plus fifteen and minus fifteen are addition and subtraction, not symbols.
Math problems really need to be understood carefully!
It seems simple, but in fact it contains complexity. Whatever you do, be serious and don't underestimate it.
Math diary, a primary school student, has 500 words.
I saw a topic "Mathematics in Life" in my math textbook today. The topic is: "China's population is about 654.38+0.3 billion. If we save 654.38+0 cents per person per day, if so, our country will save about 6.5438+0.3 million yuan. If primary school students need to save about 65438+ tens of thousands of dollars from grade one to college, then this money can be provided to 1805 children who are out of school and have no money to go to school. Wouldn't it be nice to give these money to those people? " After reading the above information, I thought: many hands make light work. Suddenly I remembered, many hands make light work? Not good, because I thought about it: if this population of about 65.438+300 million wastes 65.438+0 drops of water, then a * * wastes about 65.438+300 million drops of water, then what do you think is 65.438+300 million drops of water?
I did a small experiment: I put 1000 drops of water under the tap and weighed them with a scale. The weight of 1000 drops is 200 grams. I wrote another calculation.
1300000000÷1000× 200 = 260000000 (g)
260000000 grams =260 tons
I really don't know, it's shocking: if everyone uses one ton of water a month, then 260 tons of water can be used for two years. I went to ask my father, "How many kilowatt hours can a ton of water generate?" Dad said, "1 ton of water can generate 100 kwh of electricity." This means that 260 tons of water can generate 26,000 degrees of electricity.
Math diary, a pupil, has 500 words.
Today, I finished my homework early in the morning. My mother saw it and came up to me and said, "Zini, play a game with you!" " ""good! " I readily agreed. Mother brought a round cardboard and fixed a rotatable pointer in the center of the cardboard with a nail. The cardboard is divided into 24 squares on average, and the numbers 1-24 are written in the squares respectively. "Mom, what are the rules of the game? Say it! "I said impatiently that the rules of the game are simple, that is, when the pointer turns to an odd or even cell, the next number must be added. If it adds up to an odd number, I win; If the total is even, you win. "Mom said with a smile.
I saw that the rules of the game were very simple. I played for more than a dozen times in a row, but I couldn't beat my mother every time. My mother smiled. "Why is it always singular?" I asked my mother puzzled. Mom said, "Think for yourself!" So, I racked my brains to think, and finally reminded me of the formula that the teacher once said: odd+even = odd. Now I can see that if the pointer points to the odd number, then the next number must be even; If the pointer points to an even grid, then the next number added is odd, so no matter where the pointer points, the number added is odd. Mom won with this rule.
In the world of mathematics, there are many wonderful laws. As long as we learn math well and make good use of it, it is everywhere!
The fourth article math diary, a pupil, has 500 words.
I often think, how can I become more confident, generous and earn a lot of pocket money? I couldn't figure it out, so I asked my mother. My mother said to me, "Why don't you sell things with Lin Junbo?" "Selling things?" I shouted in surprise. I didn't sell anything, and I wanted to try it, so I nodded and agreed.
The next day, I just woke up and jumped out of bed like a monkey. After cleaning up, I felt extremely nervous and excited when my mother took me to the place where I sold things.
The fruits sold by Lin Junbo's parents are: cuckoo, peach, blueberry and corn. A kilo of rhododendron 15 yuan, cost 12 yuan; A catty of peaches in 2.5 yuan costs 1 yuan; A catty of blueberry 25 yuan costs 2 1 yuan; A corn in 2 yuan costs 1 yuan.
An aunt came to buy a cuckoo. She bought 2 Jin of rhododendron, so she used 15+ 15=30 yuan, and the aunt paid 30 yuan. Here comes another grandmother. She wants to buy 10 corn, so she uses 2 * 10 = 20 yuan. Grandma paid 20 yuan. ...
In this way, we sold things all morning and earned 360 yuan. Aunt told us that the cost of selling things is probably around 240 yuan. So the remaining 120 yuan was divided equally between Lin Junbo and me, and each of us earned 60 yuan.
The fifth primary school student math diary 500 words
The math test paper was issued, and everyone looked at the dazzling red fork, which made them feel unspeakable uncomfortable, and I was no exception. Xu teacher didn't comment on this test paper in time or criticize us, but told us two math stories. Xu teacher said, "There is a ship carrying a group of people ashore. You are the first to go ashore, the second is a seven-year-old child, the third is an eight-year-old child, and so on. How old was the first person to go ashore? " Such a childish question was unexpected, and we said with one voice, "Six years old!" "Wrong! You didn't hear me clearly. I just said that you were the first to go ashore. Are you only six years old? " We are ashamed that xu teacher is going to tell a second story. I think: we can't trip over the same stone twice.
Xu teacher added: "There is a bus with four passengers on it. At the first stop, two people get off, one gets on, and at the next stop, one gets off and two gets on. At the next stop, three people got off the bus and one got on the bus ... We kept counting how many people were left in the bus until the teacher finished. Before the teacher asked questions, many students raised their hands enthusiastically and got the answers. Xu teacher asked, "Do you know what I want to ask?" Everyone said in unison, "How many people are left in the car now?" "So, how many people are left?" "Seven people!" "You are wrong again. What I want to ask is how many stops does this bus pass? "oh! We looked at each other and were wrong again. Xu teacher said, "This shows your ability to examine questions. You were careless in this exam. You will learn a lesson after reading the test paper! "
What an unforgettable lesson! This lesson made me understand that thinking can't be taken for granted. You must first read the meaning and key words clearly.
Article 6 Primary school student math diary, 500 words.
I have been in the fifth grade of primary school and have taken countless math classes. There was a math class that I still remember, and the scene at that time was still vivid. I remember one day, the math teacher came to give us a math class. We had just learned fractional division at that time, and the teacher gave us several questions about fractional division, just one of which I couldn't do, but the math teacher said, "The classmate I want will come up and do it." I thought, don't point at me, don't point at me. But the teacher just ordered me to go up and do the problems I can't do. My heart is pounding. I can't do that problem. If I do something wrong, I will do it. That's a real pity. I still got up the courage to go to the podium to do the problem. The question is 0.4 16 ÷0.032. I made a mistake. I added two zeros. I thought the teacher would criticize me, but as a result, the teacher praised me. The teacher said, "Students, this mistake may be made by the whole class, but I said it this time. I believe everyone will not make this mistake in the future." The teacher said that the three decimal places of 0.032 should be moved three places to the right of 0.4 16, and 0.4 16 becomes 4 16, and 0.032 becomes 32, which is easy to calculate and becomes 4 16÷32. The answer is.
I will never forget this math class. If you pass this course, you will definitely not make mistakes when you encounter this kind of math problem in the future.