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Math diary's Complete Collection in Grade Three.

The first article: outsmart peaches

At noon today, the weather is very hot, and the sun is burning the earth like a big fireball. Cicada can't stand the sun, so she has to hide in the trunk and complain.

My sister and I came back from crazy play outside, so hot that we wanted to eat some fruit to quench our thirst. It happened that my aunt took out five attractive peaches from the room. My sister and I stared at the peaches on the plate, and everyone wanted another one. Aunt saw it and encouraged us to use math knowledge flexibly to have a competition-"outsmart peaches". The rule is: whoever gets the last peach will take two at a time.

My sister started first. Without thinking, she picked up two peaches and chewed them with relish. My head was running at full speed, and suddenly a coup came to me. I didn't take two first, like my sister did, but I took a Momo, and my sister was secretly pleased. I eat peaches slowly. This is because my sister has finished eating a peach, and I only ate half. When she finished eating one and a half peaches, I also finished eating the peaches in my hand. So, I picked up the two peaches left on the plate with lightning speed, shook my fingers smartly in front of her and said, "Little sister, if you want to hit me, read more books for a few years!" " Then he moved a chair and sat down, munching on peaches.

Hmm! This peach tastes really good!

Article 2: Go to the market to buy food.

Today, I followed my mother to the market to buy food. Mom said, "I will test you today. Will you buy a dish you like?" My mother gave me 20 yuan to watch my performance. "Make sure the task is completed." I said confidently. So, I walked and watched, and came to the vegetable area. At this moment, I saw an aunt selling white and tender fresh mushrooms. I think: the leftovers at home can be cooked with mushrooms. So, I asked the aunt who sells vegetables: "Aunt, how much is a catty of mushrooms?" Aunt smiled and said to me, "Little friend, this mushroom costs 7 yuan a catty. How much catty do you want?" "Aunt, I only need to buy half a catty." I think: 7 divided by 2 equals 3.5 yuan, 20 minus 3.5 equals 16.5 yuan. After thinking about it, I gave my aunt a note of money from 20 yuan, reminding her that she still needs to find me 16.5 yuan. I went to the meat department again and saw an uncle selling meat, so I asked, "Uncle, how much is a catty of meat?" "10 yuan a catty." "Then I'll buy a catty." I thought: 16.5 minus 10 equals 6.5 yuan. I handed the 10 yuan in 6.5 yuan to my uncle.

When I came out of the food market, my mother smiled and said to me, "Learn to buy food!" " When she saw that I had both meat and vegetables and 6.5 yuan in my hand.

Through this test, I feel that there are many mysteries of mathematics hidden in our lives, and the ability to learn mathematics is really important. And don't be proud. You should study hard and master more math skills in order to apply what you have learned and solve the problems around you.

Chapter three: Mathematics in the game.

Moore Manor is a game that our primary school students like very much, which allows us to relax ourselves while reading intensively. At the same time, I also found that Moore Manor also contains a lot of mathematical knowledge, and playing games can also improve our mathematical level.

There is no furniture in my house in the game. In the game magazine, I found a set of beautiful small furniture, worth 3300 mol beans. However, I only have 3000 moles of beans. What should I do to buy this furniture?

So I used my brain and found that moll bean deposit bank has interest, and the interest rate is 3% per day. In other words, my 3000 moll beans are kept in the bank, and the daily interest is 3000*3%=90 moll beans.

A day later, my deposit became: 3000+90 = 3090 mol beans;

Two days later, my deposit became: 3000+90× 2 = 3 180 mol beans;

Three days later, my deposit became: 3000+90× 3 = 3270 mol beans;

Four days later, my deposit became: 3000+90× 4 = 3360 mol beans.

That is, after the fourth day, my savings can pay for furniture!

I think there is mathematics everywhere in my life, including games. As long as you use your head, many small problems in life can be solved by mathematics!

Chapter 4: Draft Hinge

At noon today, my father and I went to Aunt Wang's water hinge shop to eat water hinges. We spent 17 yuan. After dinner, we went home In the afternoon, we took a bath and spent 20 yuan. As soon as we got home from the shower, the phone rang. My father picked up the phone and only heard the person on the phone teaching my father to buy sports shoes with me. Father asked, "Who are you?" "I am Qinchuan's mother." Then hang up. So my father took me to buy sports shoes and spent 45 yuan. He asked: How much did we spend today? I calculated that seventeen plus twenty plus forty-five is seventy-nine yuan. Ah, it cost 79 yuan today.

Article 5: Amusement Park

This summer, my mother took me to Hong Kong Disneyland. Compared with the mainland, Hong Kong is very small, with a population of about 6.6 million, with a total area of 1070 square kilometers. The smallest Disneyland in the world is located on Hong Kong Island, with an area of only 65,438+026 hectares (365,438+00 acres). The tour guide said, "If you don't play anything, just walk around for 18 minutes." Let me show you my trip to Disney!

First, we went to Mickey's photo studio and took photos with Mickey and Minnie. When we got there, we saw: Wow! There was a long queue in front of the photo studio, almost 25 meters long. My mother tried her best to take me in. Finally, we went to the Cinderella carousel to play. I got on the merry-go-round and took a closer look. The turntable has three circles, and each circle has 15. I calculated: 15× 3 = 45 (1). Wow, so many! We turned round and round on it, feeling like a happy scene when riding a horse on the grassland. I was deeply impressed by the following fantasy space trip, adventure world, mini world, the performance of the lion king and the Mickey Mouse award party.

Things in Disney are very, very expensive. A bottle of Coke 17 yuan is more than ten yuan more expensive than ours. At lunch, a bowl of noodles 50 yuan. Have you ever eaten a bowl of noodles for 50 yuan? It's really expensive! Before we leave Disney, everyone wants to buy some souvenirs. My mother bought me an umbrella for Princess Disney, which cost 100 Hong Kong dollars. On second thought, we only need 20 yuan for each umbrella here, 100÷20 = 5 (one umbrella). Wow! This is too expensive!

When I got on the bus and left Disney, my mother asked me, "How long did we play from 8 am to 6: 30 pm today?" I thought about it: 6: 30 pm is 18: 30, 18: 30 _8: 00 = 10: 30.

The bus started, and I reluctantly bid farewell to Disney Park: Goodbye, we will come again next time!

Article 6: Grandma's birthday

65438+Saturday, February 6th, is my grandmother's birthday. On my birthday, my father sent me to play badminton first. Learn badminton at10: 00-11:50 in the morning. There are 15 students in our badminton class. At the beginning of each class, Mr. Bi will let us warm up first, and each of us will play 500 balls. Then, we will pick up 50 badminton, and each person will play 3 groups, and each group will play 5 times. After that, we 1 line up, with 5 people in each line, and practice the swing. There are four steps in the swing. Whoever fails to catch the net five times during spiking will do 100 squats. I did 20 squats this time, only 1 time when I didn't surf the internet, and the most students did 100 squats. We had a good time.

1 1:50 class dismissed. Father picked me up on time and drove me to the hotel. The hotel has three floors, and we eat on the second floor. Grandma invited two tables of guests, 20 people. Mom bought a big cake. She divided the cake into 20 parts on average, and everyone could eat one twentieth of the cake. However, my brother Niu Niu wants the biggest share. What shall we do? Mom doesn't share many cakes, and nobody does. Niu Niu asked for the biggest cake, which embarrassed me. Suddenly,

I have a good idea. My mother doesn't like cakes. I gave Niu Niu one twentieth of my mother's cake, and now Niu Niu has the biggest piece, which is one twentieth of the cake. Niu Niu is very happy, and I am also very happy, because I solved the problem with the scores I learned.

Article 7: Student math diary

This semester is coming to an end, and we have entered the review stage. In math review, I have a new understanding of what I have learned.

I feel that the biggest gain from reviewing is to master some mathematical knowledge and methods. For example: decimal addition and subtraction, as long as the decimal points are aligned, it is enough to calculate with integer addition and subtraction; The method of graphic translation is: first, select a point in the translated graphic, translate several squares according to the requirements of the topic, then find another point to translate several squares, and draw a graphic with the same size as the translated graphic. For another example, to judge an axisymmetric figure, you should fold it in half along a straight line to see if the images on both sides will completely overlap.

My confusion is: if I combine what I have learned this semester, it may be difficult for me to do it. I have to think more, step by step, and try to do it right.

Article 8: Take part in the competition

On July 15, I participated in the swimming promotion training class held by Congtai Park Swimming Pool. The swimming pool is just south of my home, about 1000 meters away from my home. It takes my father about 3 minutes to take me from home to the swimming pool by bike, and our speed is about 330 meters per minute.

Training class1* * has 16 trainings, and it takes 160 yuan to buy a student ticket, plus the registration fee of 5 yuan, so the average training fee is about 10 yuan.

After I checked in, I ran into the swimming pool excitedly. Wow! The main swimming pool is very big. It is 50 meters long and 25 meters wide. I calculated with my mouth that its area is 1250 square meters.

The coach began to teach us the essentials of swimming, and then we went into the water to practice. From 8: 30 to 10: 00, it takes about 1 half an hour. I train 16 times at a time, so I always train 24 hours after the whole training.

The coach also asked me to swim 10 times, which is about (25× 2× 10 = 500m). 16 after training, I have been swimming for about 8000 meters.

After the coach's guidance and my hard exercise, my swimming level has been greatly improved compared with last year, and I am determined to continue practicing next year.