When I was at school, I found that girls were generally shorter than boys, while boys were generally taller than girls; On the physical education class, the teacher asked the short man to stand in front and the tall man to stand behind.
When I cut my nails, I found that my mother's fingers are longer than mine, and my fingers are shorter than my mother's;
When I weighed myself, I found that I was heavier than my brother, who was lighter than me.
When I got a haircut, I found that my mother's hair was longer than my father's, and mine was shorter than my father's. ...
Have you ever made such a discovery in your life? Find it quickly!
The number "χ" in composition 2 of the fourth grade of mathematics is very special. It looks like an "X".
One day, several digital friends such as "1", "2", "3" and "4" got together to compare the sizes.
Suddenly "χ" appeared in front of them and said, "Stop competing! You are no match for me! " 1 said, "How can you compare with us? You don't even know what you are, and you dare to come here and compete with us. Hey, what a young man! "
Not convinced, χ jumped in front of 1 and said loudly, "I am χ- 1=9, χ=9+ 1, χ= 10. Look, I am older than 9! "
As soon as it heard "0" in the cave, it rolled out, pulled the number "1" and ran to "χ" and said, "χ× 1=0, χ=0, which is smaller than anyone else."
After hearing "0", "χ" is no longer proud.
A hand of mathematics is flying towards us.
"Hey, the brain is going to be reimbursed!" I'm complaining about a difficult problem, and my mind is in a mess. Suddenly, I thought I would. I lit the light bulb of knowledge in the darkness of thinking. Solve by x, y principle. Simplify the problem, convert the solution according to the unit, which will bring about the distribution law conveniently, get a bracket for the difficult point, and finally use the six-step comprehensive formula to replace the unknown with X and Y, and calculate each other. In the ten-step mixed operation, add brackets, brackets and parentheses in appropriate places, and then solve X and Y, and finally get the number? Push it out! Ha ha! I can solve it in the fifth and sixth grades!
What the hell is this? So many people! Zhao, Jing, Lai, Ganges sand, 100 to the power of 1 100 million! There are billions of zeros after 100! ! ! It's so big that I'm at a loss.
Wow! 58 steps mixed operation! Son, can you answer?
Today, my mother and I went to buy fruit. When I arrived at the fruit shop, I saw the kiwifruit was big and fresh, so I said to my mother, "Mom, let's buy kiwifruit!" " "Mom went to ask the proprietress who sells fruit," How much is it? The proprietress said, "A 3 yuan." "Mom said," How much does it cost to buy nine? " I said, "Nine 3s (9× 3), 27 yuan." Mom said, "by the way, let's buy another 3 yuan apple." How much is a * * *? " I said, "27+3=30 yuan. "My mother gave me 50 yuan to pay, and the proprietress said," How much do I need to pay you back? " I said, "50-30 = 20 yuan." She said, "That's right. "
She gave me 20 yuan back, and my mother and I went home happily.
Today, I counted the number of pages and words in the book Free Travel in Thailand. I think it is difficult to count the number of words in this book, because every page of this book has at least one picture, and some are full pages of pictures. I browsed the whole book, and it is estimated that there are 500 words on an average page. I randomly counted 10 pages, then estimated the thickness of 50 pages according to the thickness of 10 pages, and then estimated the thickness of the whole book to be more than 3 pages, which should be more than 150 pages or even more than 20 pages. Then, the total number of pages in this book should be 50 * * * 3+20 = 6544. I estimated the number of pages and words. I turned to the last page, and sure enough, this book is 160, and my calculation is more accurate.
A hand of mathematics is flying towards us.
"Hey, my brain is going to be reimbursed!" I'm complaining about a problem, and my mind is in a mess. Suddenly, I thought I would. I lit the light bulb of knowledge in the darkness of thinking. Solve by x, y principle. After simplifying the problem, use unit conversion to solve it, which is convenient to take the distribution law and find the difficult braces. Finally, the six-step synthesis formula is used to replace the unknown with x and y and calculate each other. Ten-step mixed operation, proper enlargement of parentheses, then solving x and y, and finally getting the number. Push it out. Ha ha! I can solve it in the fifth and sixth grades!
? What the hell is this? So many people! Zhao Jing, beggar's Ganges, Ganges sand, 100 to 100! There are billions of zeros after 100! It's so big that I don't know what to do.
Wow! 58 steps mixed operation! Son, can you answer?
I remember before, I thought 100 million was a big number, but I didn't know how big it was.
Let's just count the exercise books. How long will it take us to count 100 exercise books? 1 serving, 2 serving, 3 serving ... 100 serving, which takes about 1 10 second. There are 1000 exercise books, 10000 exercise books, 100000 exercise books ...1000000 exercise books? Just do the math and you'll know how big 100 million is.
Calculate, hundreds of millions of exercise books will take about 1 100000000 seconds. Imagine, how many points do you need for hundreds of millions of exercise books? How long? How many days? How many years/about 183333 minutes, 30556 hours, 1273 days, 3 years! I really don't know, hundreds of millions of homework would have taken three years!
This shows that 100 million is really big!
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 composition 9 that math exam in the fourth grade.
That math exam left a deep impression on me.
Math teachers come to class for exams, all of which are decimal multiplication. I thought to myself: the teacher said all these questions, and I will definitely do well in the exam! Then I started dancing and writing. One last question, blocking me like a river. I looked at it. This mother told me. How could I forget? Just write one. Anyway, everything in front is fine.
The bell rang and shook. I'm waiting for the result.
After a few days, I got the test paper and saw the score, and my mood plummeted; 84 points! At first, I was happy to tell my mother that I could get 90 points in the exam. Oh, I shouldn't be proud.
This exam made me understand that pride can make people fall behind.
This semester, the teacher taught a new knowledge, that is, the multiplication and division of decimals. This knowledge helps me a lot!
Last night, my mother went to buy apples together. A kilo of apples is from 2.6 yuan, and my mother bought 4.5 kilos. I should pay 9 yuan. But the clerk is careless and doesn't know how to calculate. Yes 12.2 yuan. Fortunately, this semester, I used the knowledge of Protestantism, and after doing a calculation in my mind, I immediately corrected the salesman's mistake.
Not only did my aunt, the shop assistant, praise me for my cleverness and my ability to multiply and divide decimals in such a small city, but my mother also praised me for saving her 0.5 yuan on the way home, and the knowledge I learned can be applied in my life. Yes! If you don't learn this math well, it's not only 0.5 yuan that will lose, but also hundreds, thousands or even hundreds of millions!
Math composition for the fourth grade 1 1 Today, the school will hold a math competition for the third to sixth grades. I came to the classroom, which was very lively and noisy. I am good at math, but I am a little careless. I will check it carefully this time. I looked at the students in the classroom. Some students have answers, some students look flustered, some students don't care, and some students look blank. I took out my math book to review. Suddenly, a classmate pulled my skirt and asked, "Li Yuhong, you are the representative of Chinese class, so math should be ok?" Another student said, "Li Yuhong, which question do you think will be tested?" "Li Yuhong is so clever, he must have got 90 points in the exam!" My brain is too noisy to pass the exam at all. (︶︶︶︶︶︶︶) Alas, what a pain!
One day, my mother and I went to buy floor tiles.
My mother came to the tile shop and improvised a math problem for me: "haven't you learned to calculate the area?" I'll give you a math problem and see if you can answer it. "I confidently replied," what's the problem? Although you mentioned it, I am not afraid. " Mother said, "Our room should be tiled. This room is 7 meters long and 5 meters wide. Can you tell me how big the floor tile area should be? "I think: the floor of the room is rectangular, and the area is equal to the length times the width, so it is equal to 7×5=35 square meters. So I answered my mother loudly: "The area should be 35 square meters. "
Mother was very pleased, smiled and nodded, and bought a small gift to reward me on the way home!