Today, my father bought a purple tiger I looked at it. I can only see the head from the front, the tail like a pointer from the back, and only one side from the side. My mother asked me to stand in a chair and look down. At this moment, I saw the whole body of Zihu.

It turns out that objects see different results from different angles.

Chapter Two: Playing Zhu Zhu Chess.

After dinner, let's play checkers with mom! I mentioned chess. I chose the green piece, and my mother chose the red piece. Mom said you should go first, and I jumped three steps as soon as I left. My mother only took two steps, but she built a bridge for me. I took five steps at a time, and my mother only took three. After several times, all my pieces reached the finish line. When I saw my mother, I was three steps short and I beat her.

Chapter III: Measuring Height Ruler

There is a height ruler on the wall of our house. I use it to measure my height every year. Last year, my height was 1m 10cm, and this year's height is 1m 16cm,110 = 6 (cm). It has grown by 6cm this year.

I asked my mother, "When can I grow as tall as Yao Ming?" Mom said, "As long as you eat more every day, don't be picky about food and keep exercising, you will grow into a giant like Yao Ming in the future." .

Article 4: Oral calculation

In mathematics, the simplest is oral calculation, but oral calculation is the most difficult. Why do you say that? Just listen to my introduction.

Oral calculation, after a quick calculation by the brain, blurts out, but you can't wait until you work it out on the draft paper. That's a calculation, not a verbal calculation. But I'm different. A topic, like 0.75 divided by 3, I will blurt out, and the answer is 0.25, right?

Oral calculation is actually very simple, come on!

Chapter 5: Learning math well can save money.

On Sunday, my parents and I went to the supermarket to buy toothpaste. When we arrived at the supermarket, we went straight to the washing cabinet. We found that there are two ways to sell the same kind of bamboo salt toothpaste: 1, three pieces110g toothpaste, fresh and pleasant package 17.9 yuan; 2. A toothpaste 8 yuan with a weight of 150g.

My mother said to me, "Shu Ting, we are going to buy more toothpaste today and use it slowly. Which of these two ways do you think will save money? " Now I'm stumped. My mother said to me, "Today, let's put 17.9 yuan pawn 18 yuan, and you do the math!" I immediately said, "Buy fresh and enjoyable clothes to save money." Mother asked, "Why?" I said I thought so: three boxes 18 yuan, and each box of toothpaste 6 yuan 18 ÷ 3 = 6 (yuan). 150g toothpaste per box of 8 yuan, that is, more 2 yuan money to buy 40g toothpaste, so 1 yuan can buy 20g toothpaste. And if you buy 150g toothpaste, 1 yuan can't buy 20g. So I think buying fresh and pleasant clothes saves money! Hearing this, my mother said to me happily, "Great! Learning math well is really useful! "

Today, I know that mathematics is often used in daily life, and it can save money. I must learn math well!

Chapter 6: Cutting Watermelon

Last night, it was very hot. Dad stopped me when I took out a watermelon to cut. He gave me a question, the title is: cut this watermelon into nine parts and cut out ten skins. See how you cut it? At this point, I thought, well, it's simple. So, I went to get a fruit knife, put the watermelon on the table and cut it. I cut a "meter" shape. If you count, nine dollars is enough, but only nine dollars! Not convinced, I brought another watermelon. When I was about to cut it, my father stopped me. He pointed at me and said, "Oh, how many watermelons did you waste?" Let me cut it! "Dad picked up a fruit knife and told me to watch. I watched the audience carefully. At this moment, a question mark flashed through my mind. What should I do? After dad cut it, I counted it. There were only nine skins, but he cut it in the shape of a well. I looked at my father and said, "Dad, didn't you cut nine pieces?" Dad saw my puzzled look and told me the "hiding place" of the tenth piece of leather. It turned out that the tenth piece of skin was hidden under the mouth in the middle of the word "hmm" before I suddenly realized.

At this time, my father looked at me and guided me according to the situation: "There are many things in life. As long as you observe carefully, you will definitely gain something, just like cutting watermelon this time. " I nodded my head.

Chapter 7: Confusing Mathematical Problems

Yesterday, I opened the Examination Paper of the Third Grade Mathematics Improvement Class and saw a topic: There are three people in Pingping's family. My father is three years older than my mother. The age of three people in the family this year is 765,438+0 years old, compared with 49 years old eight years ago. How old is Pingping this year? How old are mom and dad?

I looked at it and thought, wow, this is so simple! So 3× 8 = 24 (year) 7 1-24 = ... Oh, something is wrong! I thought about it, but I still don't understand. Dad looked at the question and said, "I have encountered this problem before." 7 1-24 = 47 instead of 49. I know, this shows that Pingping was not born eight years ago! How nice to think so! "

I listened to my father's prompt, picked up a pen and did it excitedly: So Pingping is 6 years old this year, his father's age is (7 1-6+3) ÷ 2 = 34 (years old), and his mother's age is 34-3 = 3 (years old).

I checked, wow, yes, that's right.

I think: these similar math problems are easy to confuse people, so we must remember them to avoid being cheated.

Chapter 8: 2 1 point game

On Sunday, Yang Wen and I played 2 1 point. The rules of the game are simple: everyone draws four cards respectively, and then uses these calculation methods of "+,-,×, ⊙", and the final number must be 24.

The game started, and we each drew four cards. Alas! How come my cards are so bad! Listen, four people are all trump cards. At this moment, I only heard Yang Wen say, "I can do it. You see, 5+5= 10, 10×2=20, 20+4=24. " I lost the first round. But I am not discouraged, because there are still opportunities in the future, and I must seize them and strive for them. I drew four more cards "6, 5, 8, 3". I was so excited that I blurted out immediately: "6-5= 1, 8× 3 = 24,24 ÷1= 24. Now 1 is even with 1. "

Yang Wen said, "Anyway, I will definitely beat you in the next round." The third round arrived, and I drew four more cards "10, 9, 6, 10". I was dumbfounded at first sight. Suddenly, Yang Wen shouted: "6× 4 = 24,24+1-1= 24. 2 1 I won. " I watched him smug and helpless.

Although I lost the game, I think 24 o'clock is really interesting and math is really wonderful. I must study math well in the future and use the mixed operation of "+,-,×, ⊙" flexibly. In the next 2 1 point game, I must skillfully use it and become a master.

Chapter 9: Interesting Math Games

Yesterday, I saw the clever speculation about age and money in my pocket in the fourth grade entrance class, which immediately attracted me.

It says, multiply your age by 2, plus 5, and the number you get will be multiplied by 50, plus the money in your pocket (not more than 10 yuan, calculated in terms of angle), and then subtract the number of days in a year (normal year) to lengthen 1 15.

I read this topic, and if I didn't believe it, I gave it a try. My age is 9 years old, and the money in my pocket is 5 yuan 50 cents. I put 9× 2 = 18, 18+5 = 23, 23× 50 =11150+55 =/kloc-0.

In this way, I divided 955 into 9 and 55 segments. Nine is my age, and 55 is the money in my pocket.

How's it going? This math game is also very fun! Please try it and see if it's right.

Chapter 10: Picking pine cones

Winter is coming, and the little squirrel has to prepare food for the winter.

One day, the little squirrel came to the forest with a big bag on his back and said to Grandpa Pine, Would you please give me your pine cone? Grandpa Pine was generous and said: Pick as many as you want. The little squirrel is very happy. He picked it up and sang. Soon the bag will be full. Grandpa Pine asked: How many did you pick? The little squirrel said, Oh, I forgot! Grandpa Pine smiled and said, "I planted 16 pinecones, and there are nine more. If you can figure out how much you picked, I'll let you carry it. " The little pine tree is in a hurry and can't be counted. What shall we do? If Grandpa Pine won't let him take it away, what will he eat in winter? I will help it.

In math class, the teacher said: knowing the total number and finding the partial number is to remove the known partial number from the total number and get another partial number, which is calculated by subtraction. I soon figured it out that the little squirrel picked 16-9=7 (pieces).

Chapter 11: Interesting Travel Problems

Sitting bored today, I said to my father, "Let's do the Olympic math problem together!" " "ok!" Dad readily agreed.

Because my trip problem has not been consolidated, I will review the trip problem first. Dad said, "Let me introduce the itinerary first." "all right." I clap my hands happily. Dad began to introduce meaningfully: "Our daily life is inseparable from walking and riding, and objects are moving all the time. This is the so-called' walk'. Having a' trip' means that it takes time to generate a distance, which constitutes three important relationships in the trip problem: distance, speed and time. The application of studying these three relationships is called travel problem.

The relationship between these three quantities can be expressed by the following formula:

Distance = speed * time

Speed = distance/time

Time = distance/speed

After listening to my father's introduction, we began to do the example 1. Example 1 It's like this: The home in Obana, Sung Jae Lee is 400 meters apart, and they both started from home and walked on the same road at the same time. Xiaohua walks 60 meters per minute, and Li Cheng walks 70 meters per minute. How many meters are they apart after 3 minutes? "This question is too simple. As long as you use Obana's speed and time, you can calculate the walking distance of two people. Then subtract the distance they walked from 400 meters and find out how many meters they are apart after three minutes. " I am proud to say. Dad smiled and said, "I don't think you have considered the problem comprehensively." The title does not say whether we are moving in the opposite direction, or moving in the opposite direction, or moving in the same direction. " "Oh, I see." The answer to this question is as follows:

(1) in the opposite direction: 400-(60+70)*3= 10 (m)

A: After 3 minutes, the distance between them is 10 meter.

(2) Back: 400+(60+70)*3=790 (m)

A: Three minutes later, they were 790 meters apart.

(3) Same direction: 400-70*3+60*3=370 meters in front of floret.

A: Three minutes later, they were 370 meters apart. xiaoxue 123

(4) Same direction: 400-60 * 3+70 * 3 = 430m in front of Li Cheng.

A: Three minutes later, they were 430 meters apart.

Ah! The travel problem is really interesting!

Chapter 12: "Chickens and rabbits in the same cage"

Have you ever heard of the problem of "chickens and rabbits in the same cage" This question is one of the famous and interesting questions in ancient China. About 1500 years ago, this interesting question was recorded in Sun Tzu's calculation. The book describes it like this: "There are chickens and rabbits in the same cage today, with 35 heads on the top and 94 feet on the bottom. The geometry of chicken and rabbit? These four sentences mean: there are several chickens and rabbits in a cage, counting from the top, there are 35 heads; It's 94 feet from the bottom. How many chickens and rabbits are there in each cage?

Can you answer this question? Do you want to know how to answer this question in Sunzi Suanjing?

The answer is this: If you cut off the feet of every chicken and rabbit in half, then every chicken will become a "one-horned chicken" and every rabbit will become a "two-legged rabbit". In this way, the total number of feet of (1) chickens and rabbits changed from 94 to 47. (2) If there is a rabbit in the cage, the total number of feet is more than the total number of heads 1. So the difference between the total number of feet 47 and the total number of heads 35 is the number of rabbits, that is, 47-35 = 12 (only). Obviously, the number of chickens is 35- 12 = 23.

This idea is novel and strange, and its "foot-cutting method" has also amazed mathematicians at home and abroad. This way of thinking is called reduction. Reduction method means that when solving a problem, we do not directly analyze the problem first, but deform and transform the conditions or problems in the problem until it is finally classified as a solved problem.

Chapter 13: the seesaw problem

In math class, the teacher said: Have the students ever played on the seesaw? The students all said they had played. The teacher said: how to play, who can tell the students?

After a while, the teacher took out a scale from under the platform and put it on the platform, telling us how the teacher did it. The teacher put two oranges on the left plate and an apple on the right plate. The teacher said: These two oranges are as heavy as an apple. At this time, the teacher took an orange from the left plate, only to see the right plate drop and the left plate become warped. The teacher asked us: What is it like? The seesaw teacher asked again, "Why is this?" Students say: apples are heavy, oranges are light. The teacher said: How many oranges are compared with how many apples? I saw the teacher take down the apple again, and then put a small packet of biscuits on the weighed plate. As a result, the orange side fell down and the biscuit side became warped. The teacher asked again: Why is this? "Oranges are heavy, biscuits are light." Please have a look again. The teacher added a packet of biscuits, but they stuck together. The teacher added another bag and said that the plates on both sides were flat. The teacher asked again: Why are the plates on both sides the same height? The students scrambled to answer. The teacher said: apples are heavier than oranges, and oranges are lighter; An orange is lighter than a packet of biscuits. Do the students know how to compare weights?

Article 14: "Cunning" Little Cousin

Today, I went to menstruation's house and saw my 4-year-old brother wearing a Tang suit, so my mother played a joke on him.

Mom said, "Xiao Pang, your clothes are really nice. Can you lend them to my aunt? "

Xiao Pang winked and said, "No, you will be very hot in this suit."

Mother added, "My aunt is most afraid of the cold."

Xiao pang immediately pretended to be cold and said solemnly, "I just made a mistake." This suit is really cold. " As he spoke, he had a few cold wars.

Mother fought back a smile and said, "It's cold or not, as long as I put on more clothes inside."

Xiao pang is very anxious. He pouted and shouted, "but the clothes are too small for you!" " "

Everyone laughed when they heard it.

Chapter 15: Problems

In the evening, I saw a problem in the Olympiad Book: the number of apple trees in the orchard is three times that of pear trees. Master Lao Wang fertilizes 50 apple trees and 20 pear trees every day. A few days later, all the pear trees were fertilized, but the remaining 80 apple trees were not fertilized. Excuse me: How many apple trees and pear trees are there in the orchard?

I am not intimidated by this question, but it can stimulate my interest. I think the apple tree is three times as big as the pear tree. If two kinds of trees are to be fertilized on the same day, Master Lao Wang will fertilize "20×3" apple trees and 20 pear trees every day. In fact, he only fertilizes 50 apple trees every day, which is 10, and the last 80 trees. Therefore, Master Lao Wang has been fertilizing for 8 days. 20 pear trees a day, 8 days is 160 pear trees. According to the first condition, there are 480 apple trees. This is to solve the problem with the idea of hypothesis, so I think the hypothesis method is really a good way to solve the problem.

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