Mathematics Harvest Diary 600 words 1
We learned grams and kilograms in math class. It turns out that life can express the weight of an object in grams or kilograms. Usually, we use "gram" (g) as the unit of lighter items, such as the weight of a piece of chewing gum, a box of children's toothpaste, a coin, a box of biscuits, etc. We use "kg" as the unit of heavier items, such as the weight of a bucket of laundry detergent, a box of apples, a bag of rice and my weight.
On the way home from school, I told my mother that the teacher asked us to look for knowledge related to quality units in our lives. So, my parents took me to the supermarket. As soon as I entered the supermarket, I saw rows of milk neatly placed in front of the supermarket. I looked at it and found that the net content of each box of milk was 250 grams. At this time, my mother asked me, "A box of milk is 12 box, and each box of milk is 250 grams. How many kilograms is a box of milk?" I use 12×250g=3000g. In classroom learning, we know that 1000g= 1kg, so 3000g is equal to 3kg. The aunt next to me listened and praised me for being so smart.
Later, my parents and I went to buy 1 kg apples. My mother told me, "In life, people are used to using' Jin' and' two' to represent the weight of an object, 2 Jin = 1 kg, 1 kg =500 grams." "Oh, so that's it! Then today we bought 1 kg apples, 2 kg. A * * *, there are five apples. " I'm happy to answer. When weighing, I also found that most supermarkets use electronic scales. I heard the teacher say that heavy objects need to be weighed. I haven't seen it yet. I must go and have a look in person when I have the chance.
Today I am very happy, because I have learned a lot of knowledge through my life practice and solved the problems in my life with what I have learned from my textbooks. Mathematics knowledge is really everywhere! I must study math hard and use what I have learned to solve more problems in my life.
Mathematics Harvest Diary 600 words 2
At this moment, the bell rang and I rushed into the classroom.
I love literature because I like ancient poems. When I felt helpless about life, I thought of Li Yu, the king of national subjugation. He once said, "How much sorrow can you have, just like a river flowing eastward." Because poetry can soothe my inner wounds, only poetry can understand me at this time. I regard poetry as my friend and poetry as my pen pal.
It is not easy to study in university. Isn't studying hard at ten cold windows just to fly high through the college entrance examination? When I entered the university, I found that the university was not my ideal paradise. I say to myself repeatedly every day, "What have we really learned after graduating from college? I don't think college is even as good as high school. Universities recruit students from all over the world. Every student comes to a different school, and their quality varies greatly. A person's poor grades show that he is of high quality. At this time, I am sitting in the classroom having a math class. The classroom is too noisy. As far as discipline is concerned, people who don't know think we are holding a debate. Teachers don't care about discipline either. She left after class.
From the time I entered this school, I passed the written interview and entered the boys' department of the student union. The main duty of this department is to check hygiene. Really tired! I just got up earlier than the chicken and went to bed later than the dog. I get up at 5: 30 in the morning to run. According to the regulations of this department, I have to check the dormitory at night and go to bed at least at eleven o'clock. Joining the student union is mainly about joining the party, followed by exercising yourself. It's not easy to stick to it!
I walked out of the classroom quickly when the bell rang. It's raining heavily outside. Fortunately, I brought an umbrella. I like to plan ahead best. In Zuo Zhuan, it is said that if you think about it, you will be prepared.
I can confidently say to others, "If you are determined to do anything on the road, the world will make way for you."
Mathematics Harvest Diary 600 words 3
In recent weeks, we have learned the multiplication of two digits, and what kind of multiplication can be calculated skillfully. Let me talk about one of them.
In today's math class, the teacher asked us to calculate several multiplication formulas as follows:15×1,27× 1 1, 13× 1, 34× 65438. Many students worked out the figures right away, but I still didn't write them out, so I was worried.
I only heard the teacher say, "Stop, students who haven't written well should stop writing. Listen to other students' methods. Why do they calculate so fast? " Ye, the fastest student in our class, said, "I calculate so fast because one factor in these multiplication formulas is 1 1, and there is such a trick." "The hundredth digit of the product is the number on the tenth place of another factor, the tenth digit of the product is the sum of the number on the tenth place and the number on the fourth place of another factor, and the fourth place of the product is the number on the fourth place of another factor. For example, 15× 1 1, one percent of the product is 1, one tenth of the product is 1+5=6, and the unit of the product is 5, so15×1/. Do you understand? " "I understand!" The students said in unison. "Why is this possible?" I asked the teacher. The teacher smiled and said, "Yes, who knows why?" The students shook their heads. "We can look at it vertically. Can we find any little secrets? " So we all started to arrange vertically. Under the guidance of the teacher step by step, we finally found that the number on the product ten is the sum of 1 10 and 50. Oh, that's it. I see.
Later, the teacher asked us to calculate 47× 1 1. Some students said 4 17, some students said 4 1 17, and some students said 5 17. I raised my hand to explain to my classmates, "The unit of product is 1×7=7, the ten digits of product are 4+7= 1 1, the decimal digits are 1, and the decimal digits are 1. After listening to my method, the students all nodded and said yes, and my mind was also happy.
Later, the teacher came up with these questions: 1 1×75, 22×25, 18×33, and we all worked them out quickly. Students, can you work it out?
A class passed unconsciously, and the teacher asked us to sum up our gains. Everyone has their own opinions, and everyone's face is full of smiles. Finally, the teacher sent us this sentence: "To learn mathematics, we should not only know what it is, but also know why."
Mathematics Harvest Diary 600 words 4
This Thursday, a good thing happened that excited me.
At the end of a class on Thursday, I sat in my seat. The math teacher called me, Liu Yiheng and He Yi and said to us, "After school in the afternoon, your class will have a China Cup school tryout. You three are the top three in the total test scores of the four units in your class, and three representatives from the other two classes came to participate in the selection, and then three of your nine were selected to participate in the China Cup. " Hearing this, I am both excited and nervous. I am very happy to have this opportunity, and I am also nervous about the strength of my competitors.
On this day, I spent it in the ambivalence of excitement and tension.
School is almost over, and we are waiting for the math teacher and other students in the classroom.
The math teacher came, and so did the students from other classes. The math teacher said to us, "Do two questions one by one, and the exam time is 30 minutes. Whoever does it quickly and well will have the opportunity to participate in the China Cup. " Finally, she added, "If you can get a place in the China Cup, many middle schools will recruit you." After that, the teacher began to hand out papers.
I read and do topics with a nervous and excited mood. The first question is relatively simple. I solved it by solving the equation, and it was finished soon. I can't help feeling a little smug. But the next question hit me hard, and the ever-changing amount dazzled me. I calculated it on paper again and again, but I still didn't figure it out. I am depressed, but I can't help it. I stared at the topic, thought hard while watching it, and finally understood it. I listed the equations and solved the problem by cross multiplication. After checking, I handed the paper to the teacher and began to do my homework. Soon, 30 minutes passed. After all the students handed in their papers, the teacher immediately corrected them and announced the results of the selection: "Liu Jingwen got it right ..." When I heard this, my heart was pounding and I was so excited that I couldn't describe it in words.
This time, I, Wu Xiaotao from Class Two and Wu from Class One went to see the China Cup.
The three of us stayed, listened to the teacher's time and place, and went home.
Soon, I will represent my school in the China Cup. Can I enter the finals and finals? There is confusion ahead.
Mathematics Harvest Diary 600 words 5
People in ancient China discovered and applied Pythagorean Theorem thousands of years ago, and understood the mathematical principles. Readers who know a little about plane geometry know that the so-called Pythagorean theorem means that in a right triangle, the sum of the squares of two right-angled sides is equal to the square of the hypotenuse.
Using hook (a) and rope (b) to represent right-angled triangle respectively to get two right-angled sides, and using chord (c) to represent hypotenuse, you can get:
Hook 2+ rope 2= chord 2
Namely:
a2+b2=c2
Pythagoras theorem is called Pythagoras theorem in the west, and it is said that Pythagoras, a mathematician and philosopher of Pythagoras, first discovered it in 550 BC. In fact, this mathematical theorem was discovered and applied in ancient China much earlier than Pythagoras. If it can't be verified that Dayu's flood control is a long time ago, then the dialogue between Duke Zhou and Shang can be determined in the Western Zhou Dynasty around 1 100 BC, more than 500 years earlier than Pythagoras. Hooking 3 strands, 4 strings and 5 strings is a special application of Pythagorean theorem (32+42=52). So it should be very appropriate to call it Pythagorean Theorem in the field of mathematics now.
In the later book "Nine Chapters of Arithmetic", Pythagorean Theorem got a more standardized general expression. The book Gou Gu Zhang said: "Multiply the hook and the stock separately, then add up their products and make a square root, and you can get the string." Put this passage into an equation, that is:
Chord = (hook 2+ rope 2)( 1/2)
Namely:
c=(a2+b2)( 1/2)
Theorem:
If the two right angles of a right triangle are A and B and the hypotenuse is C, then the square of A+the square of B = the square of C; That is to say, the sum of squares of two right angles of a right triangle is equal to the square of the hypotenuse.
If three sides A, B and C of a triangle satisfy A 2+B 2 = C 2, for example, a right-angled side is 3, a right-angled side is 4, and the hypotenuse is 3x3+4x4 = x x, and X=5. Then this triangle is a right triangle. (called the inverse theorem of Pythagorean theorem)