Mathematics Diary 300 words

At noon today, I was doing my math summer homework. As I was writing and writing, I unfortunately encountered a very difficult question. I thought about it for a long time and couldn’t figure out the reason. The question is like this:

There is a cuboid with two areas on the front and the top. The product of is 209 square centimeters, and the length, width, and height are all prime numbers. Find its volume.

I saw it and thought: This question is really difficult! What is known is only the product of two surface areas, and the volume must also know the length, width, and height, but it does not give any hint at all. How to get this!

Just as I was scratching my head and head anxiously, one of my mother’s colleagues came. He first taught me to use equations to solve problems, but I was not very familiar with the equation method. So, he taught me another method: first list the numbers, and then eliminate them one by one. We first listed many numbers according to the requirements of the topic, such as: 3, 5, 7, 11 and other prime numbers. Then we started to exclude, and then we found that only the two numbers 11 and 19 were left. At this time, I thought: one of these two numbers is the front of the cuboid in the question, the common edge length on the top; the other is the front of the cuboid, the sum of the other edge lengths (and the lengths are all prime numbers) except the previous one. So, I started to distinguish which number each of these two numbers was.

Finally, I got the result, which is 374 cubic centimeters. My calculation formula is: 209=11×19 19=2+17 11×2×17=374 (cubic centimeters)

Later, I used the knowledge I learned this semester: decomposing the mass factors to check this calculation Question, the result is exactly the same.

After solving this problem, I was happier than anyone else. I also understand a truth: mathematics is full of mysteries, waiting for us to explore.

Playing darts

Today, my dad and I went out and bought a dart. When I got home, my father hung the darts on the wall, played with me, and taught me how to keep score.

This dart is round and divided into four circles along the radius. The red circle in the center is 50 points, the second green circle is 25 points, the third red and green circle is 3 times the scoring area, and the fourth red and green circle is 2 times the scoring area. The outermost part is composed of 20 black and white cells, each of which corresponds to a score. The four colors of black, white, red and green plus stainless steel partitions form a beautiful pattern.

There are six darts. At the beginning, we did not follow the rules of the game. Instead, each person threw 3 darts to see who scored the most points to determine the winner or loser. For example: one team scored 20 points, the other scored 7 points in the triple zone, and the third team scored 18 points. How to calculate it? That is 7×3 + 20 + 18 = 59 points

Playing darts not only exercises my oral arithmetic skills and hand-eye coordination, but also brings me a lot of happiness. I like to play darts.

Thoughts after learning a difficult problem

Today, I learned a difficult problem, and I think I learned it very well. Because I used my brain. Dad said: "If you don't know the questions, you should use your brain and think more." For example, I saw a question: Do you know how much 388÷4 equals? We haven't learned how to divide three-digit numbers by one-digit numbers, but I want to try it. I calculated it like this at first. 3 is not enough to divide by 4. I can add 8 to it. Divide 38 by 4 to quotient 9. I What should I do if I think about 4×9=36? Hey! Yes, I put 38-36=2, then added 2 and 8, and used 28÷4=7. I said happily: "This question is equal to 97!" Dad praised me.

Mathematics Diary (1)

Today, my parents and I went to Shijiazhuang Zoo. Buy a train ticket first, which costs 25 yuan for adults and 13 yuan for children. ***It cost 63 yuan.

When we got there, we spent 188 yuan staying in a hotel. The next day, we went to the zoo. It cost 45 yuan when I went there and 40 yuan when I came back. The zoo ticket is 40 yuan for adults and 30 yuan for me. The train fare back is the same as when you came. On the train, I calculated that I spent 509 yuan not counting meals.

I was very happy these two days, because not only did I see a lot of beautiful scenery, but I also learned about various ticket prices!

Mathematics Diary (2)

Today, my father and I went to the small supermarket at the door to buy things. When I got there, my father gave me 10 yuan and asked me to go shopping by myself.

After I went in, I first took a pack of crispy noodles and spent 5 cents. Then I got a pack of shrimp crackers and a pack of sweet noodle sauce, which cost 1.5 yuan. Then I took two pieces of white chocolate and spent 5 yuan. Finally, I bought another bottle of iced black tea and a pack of crispy noodles, which cost 3 yuan. All 10 yuan was spent.

This time not only let me know how to spend money, but also let me know the prices of some items.

Feng Zhaowei’s Mathematics Diary

Mathematics Diary (1): How much money did my mother earn

On May 18, my mother took me to the bank to buy funds.

I asked my mother: "What is a fund?"

My mother said: "A fund is a financial management method."

"What is a financial management method?" I still don't understand.

"It is to invest your own money through reasonable allocation to obtain greater returns. For example, investing in stocks, funds, bonds, or depositing it in a bank, etc." Mom explained.

"So we want to buy a fund?" I asked.

"Yes. I chose to buy a fund because its returns are higher than bank interest and less risky than the stock market." Mom continued to explain patiently.

"Then how much money do you earn?" I asked.

"This requires you to do the math. I bought 10,000 shares at 1.03 yuan and sold them at 1.18 yuan. I have to pay a handling fee of 0.02 yuan to the fund company for each share. How much do you think I earned?”

I quickly took out my pen and wrote out these calculations: 10000×﹙1.18-1.03-0.02﹚﹦1300 (yuan)

My mother looked at it and smiled and said: "Baby, you are so smart!"

Ha, I have become a little expert in financial management.

Mathematics Diary (2): Buying groceries

On Sunday, my grandma and I went shopping. There are many vegetables and fruits in the market. Here are the prices of various vegetables: eggs: 3.5 yuan, beans: 1.3 yuan, soybeans: 2.5 yuan, cucumbers: 0.8 yuan, watermelons 0.6 yuan, apples: 1.5 yuan. We bought one kilogram of eggs, one kilogram of beans, one and a half kilograms of cucumbers, two kilograms of soybeans, nine kilograms of watermelons, and four kilograms of apples. The total cost was 3.5×3+1.3×1+0.8×1.5+ 2.5 × 2 + 0.6 × 9 + 1.5 × 4 = 24.4 yuan

Haha, you see, I have figured it out, you have to take me with you when you buy groceries in the future!

Jin Peixuan Mathematics Diary

Mathematics Diary (1)

Sunny Saturday, July 29, 2007

Yesterday, when I was writing a mathematics diary at home, I mentioned thousands of things. Meter is the unit of length, so I asked my dad: "How many kilometers does it take to go from home to school in one day?" Dad said: "There are seven kilometers in one foot." Dad asked again: "Do you know how many kilometers it takes to get to and from school in one year?" How many kilometers do you need to walk? How much does it cost for gasoline? Our car needs 6 liters of gasoline for 100 kilometers, and 1 liter of gasoline costs 5 yuan.”

Have you figured it out? See if my calculation is correct? There are 365 days in a week this year, 90 days in a week during winter and summer vacations, and 72 weekends in a week. There are still 203 days left, which means that there are 203 days of school in a year, and there are two pick-ups and drop-offs a day: 4× 7=28 kilometers, then the distance traveled in one year is: 203×28=5684 kilometers! The required gasoline cost is: 5684×(6÷100)×5=1705.2 (yuan).

Mathematics Diary (2)

Sunny Sunday, July 29, 2007

Today, I came up with a math problem: Our family of three came from Handan Is it cheaper to go to Qinhuangdao by train or car? I'm going to start counting now! Everyone, please pick up your pen!

Haha! I've figured it out. Let’s check it out together! Qinhuangdao is 700 kilometers away from Handan. The fuel consumption is - 10 liters of oil for 100 kilometers, 5 yuan per liter of oil, and 300 yuan toll. One pound of oil: 700÷10=70 (liters) of oil. One pound of oil: 70×5=350 (yuan). Total: 650 yuan. Now it's time to take the train. Adults: 220 yuan for a hard sleeper. Children: 60 yuan for a half-price hard sleeper. Buy two sleepers, one with a hard seat, and one adult and one child can sleep in the other with a hard sleeper. Total: 500 yuan. The answer is out!

Mathematics Diary (3)

Sunny, August 5, 2007

Today, my mother is going to enroll me in a swimming class, and there is also Chen Manjia. After returning home, my mother asked me a question: It costs 150 yuan for 20 days at Bibo swimming pool, 2 hours a day. At the New Century Swimming Pool, 100 yuan for 15 days, 1 hour per day. Where is the deal?

I’m going to start forgetting it! Are you ready? Please refer to my answer first! First, calculate how many hours it takes to study in one day: 20×2=40 (hours) 15×1=15 (hours). Then calculate how many yuan per hour: 150÷40=3 yuan, 7 jiao and 5 minutes, 100÷15= 6 yuan, 6 cents and 7 cents is still a good deal at Bibo. Have you done the math?

Mathematics Diary (4)

Sunny August 6, 2007

I discovered a math problem when I was drinking milk today, that is, I have to drink milk every day (Both mom and dad drink it, but this time it doesn’t count.) A bottle of yogurt and a bag of milk cost one yuan for a bottle of yogurt in the morning and one yuan for a bag of milk in the evening. How many bottles of yogurt and how many bags of pure milk do you drink in a year? ***How ??much does it cost?

Is everyone OK? Look at mine! Calculated in a normal year: if you drink 365 bottles of yogurt and 365 bags of milk in a year, it costs 720 yuan per day, so in a leap year it will be 722 yuan. I started drinking milk when I was two years old and have been eight years old. How many bags of milk did I drink per day and how much did I spend per day? There are two in leap years and six in ordinary years.

Spending money per day in a normal year: 720×6=4320 yuan; Leap year: 722×2=1444 yuan; 4321444=5764 yuan per day! Wow! One***5764 yuan! Is everyone done with it?

Mathematical Diary (5)

Sunny Friday, July 28, 2007

Today, on the way to Qinhuangdao, I discovered a mathematical problem, which is Handan How long does it take to get to Qinhuangdao?

The distance from Handan to Qinhuangdao is 700 kilometers, and the car travels 100 kilometers per hour. It takes 30 minutes to go to the toilet, 20 minutes to refuel, and an hour to eat. Have you done the math? I calculated it using the formula: time = distance ÷ speed: 700÷100 = 7 (hours) 7 hours + 1 hour + 30 minutes + 20 minutes = 8 hours and 50 minutes. So it takes 8 hours and 50 minutes to get from Handan to Qinhuangdao. Have you figured it out?

Liu Yuchu’s Mathematics Diary

Mathematics Diary (1)

---August 1

This is how I arranged this evening, Eat 300g of rice and 200g of stir-fried vegetables for dinner, which takes about an hour. After dinner, I rested for 20 minutes and then went out to play racing. The racing car ran 1,200 meters per minute. I couldn't even catch up.

When I got home, I turned on the TV and watched the news for half an hour. Then I took out "Little Doudou outside the Window" and read more than 20 pages. When I was ready to wash up and go to bed, I squeezed out 1cm of toothpaste, filled it with 100g of water, and brushed it up and down, left and right for 3 minutes. Use 500g of water to wash your face for 8 minutes. After everything is done, I will sleep comfortably.

Mathematical Diary (2)

----August 7

I will fly back to Shijiazhuang from Hong Kong at noon today, at the Hong Kong International Airport I saw that the plane we were going to take was a Boeing 737, which is a medium-sized aircraft.

Entering the cabin, the aisle in the middle is about 50cm wide, with three seats on each side. There are 25 rows at the end and 8 business seats at the front. After the plane took off, I saw on the pop-up TV screen that the plane quickly rose to an altitude of 7,000 meters and a speed of 830 kilometers per hour. When ordering, I drank 300 ml of ice sprite and ate 200 grams of rice. People around me ate with gusto. After lunch, the beautiful stewardess brought me a blanket 150cm long and 80cm wide, and I fell asleep in a daze. After about two and a half hours, we arrived at our destination smoothly.

Lu Qihai’s Mathematics Diary

Mathematics Diary (1): A Dazzling Vegetable Market

July 22, 2007

Today , my grandma and I went to the vegetable market to buy vegetables. There are so many products in the vegetable market! There are green rapeseed, red carrots, and all kinds of fruits... "It's so cheap, cabbage is 1.2 yuan per pound!", "Come on, potatoes are 2 yuan per pound. "!", "The braised tofu is nine cents per catty, guaranteed to be enough!" The market is full of vendors.

My grandma and I came to a butcher shop and saw the sign saying: "Chicken legs are 8.5 yuan per catty, and pork belly is 9.5 yuan per catty." Grandma asked me: "Let's make chicken leg stew for noon today. Tofu!" "Great, this is my favorite dish" I replied happily. So, grandma bought 2 pounds of chicken legs and 3 pounds of tofu. I asked my grandma what she wanted to eat, and she said: "Fried cabbage!" So we bought another pound of cabbage.

On the way home, my grandma told me that her boss brought 100 yuan and asked me how much money I had left after buying chicken legs, cabbage and tofu. I calculated silently in my mind: chicken legs 8.5*2=17 yuan, tofu 0.9*3=2.7 yuan, cabbage 1.2*1=1.2 yuan, *** spent 17+2.7+1.2=20.9 yuan, and there is still 100- 20.9=79.1 yuan. After I told my grandma the answer, she said happily: "Congratulations on getting the answer right, my grandson is so smart!"

Mathematics Diary (2)

August 23, 2007< /p>

In the badminton class this afternoon, the teacher asked us to run three laps around the playground. He also emphasized that if anyone is overtaken by another student, he will be punished by running two more laps. I think, if you are overtaken by someone else, you have to run 5 laps in one lap of 400 meters, 5*400 meters = 2000 meters = 20000 decimeters = 200000 centimeters, my God! I feel like fainting just thinking about such a big number.

I started running. I could still follow the team in the first lap, but when I ran to the second lap, I felt that my body was getting weaker and weaker, my legs were getting heavier, and the sun seemed to be getting farther away from me. It's getting closer and closer, and I can't wait to sit down on the playground.

Seeing that I was about to be overtaken, I gritted my teeth and rushed forward. Not only was I not overtaken by others, I also overtook a fat classmate in front of me!

This class is very meaningful to me because I defeated myself again!

Mathematical Diary (3) Happy Journey

July 27, 2007

Today, our family and three of my father’s classmates took a bus to Qinhuangdao for a trip . On the way, I asked the driver how fast the car could reach Qinhuangdao and how many hours it would take to get to Qinhuangdao? He replied that it could travel 100 kilometers per hour and it would take about 8 hours to reach Qinhuangdao. 8*100=800 kilometers, 800 kilometers from Handan to Qinhuangdao, I think this is so far! My mother said: "Son, what time do you think it will be when we arrive at our destination?" I calculated silently in my mind: We set off at 10 a.m. and traveled about 8 hours, that is, 18=18, ah! It’s already 6pm when we arrive in Qinhuangdao. It’s such a long time!

On the way, I told jokes and played solitaire games with the children, and I was very happy. When our car was refueling at a highway gas station, my father's classmate Uncle Zhang asked me: "Lu Qihai, diesel is 4.64 yuan per liter. We need to refuel 50 liters each time. How much does it cost?" I calculated: 4.64*50 =232 yuan, "232 yuan!" I answered. Everyone said: "Congratulations on the correct answer." Uncle Zhang asked again: "We have to refuel 4 times on the way back and forth. Can you tell me how much it will cost us?" I answered very confidently: "That's good. It’s a good calculation, 232*4=928 yuan!” People in the car praised me for being really good at math, and I felt very happy.

Due to traffic jams on the road, we arrived in Qinhuangdao 4 hours later than scheduled and at 10pm. Although I was very tired, I was very excited because I could finally go to the beach to play.

Ma Linlin’s Mathematics Diary

Mathematics Diary (1)

Yesterday morning my father and I set off at 6:30, walking at an estimated speed of 50 meters per minute , arrived at Zhaoyuan at 7:00. Today we still set off at 6:30 and arrived at Zhaoyuan at 6:55. Dad asked me what my speed was today.

I said this is a distance problem. You should first know the time, speed and distance. Their relationship is: speed × time = distance, distance ÷ time = speed, distance ÷ speed = time. I learned from yesterday You can tell how far it is from my home to Zhaoyuan. The time taken is 7:00-6:30 = 30 minutes, the speed is 50 meters per minute, so the distance is 30×50=1500 (m). Today we walked the same distance as yesterday, but the time taken was 6:55 - 6:30 = 25 minutes, so today's speed is 1500÷25=60 (m/min).

Mathematics Diary (2)

Today I discovered a problem: There are two buildings in our family courtyard. I measured them by foot and they are about 40 meters apart. If they are planted every 4 meters, How many trees can be planted with one tree? I think this is a tree planting problem. If I want to know the answer, first find out how many 4-meter intervals there are. Then think about the two ends where trees cannot be planted because there are buildings. It is a tree planting problem without planting trees on both ends, so use the number of intervals minus 1. It is the number of trees that can be planted, and the formula is: 40÷4-1=9 (trees).

Tian Yifan’s Mathematics Diary

Sunny Thursday, July 26, 2007

Book Purchase List

Dad bought me four books from Shijiazhuang Books, I took a closer look at the payment receipt. There were two math books, each costing 11 yuan; two English books, one costing 13 yuan and 6 cents, and one costing 15 yuan. The final total price marked was 35 yuan and 40 cents.

I started to calculate: 11 yuan + 11 yuan + 13 yuan 6 cents + 15 yuan = 50 yuan 6 cents.

I said: "That's not right, Dad! You should have paid the bookstore 50 yuan and 60 cents! Why did the total price marked in the end be 35 yuan and 40 cents."

"You Forgot to give it 30% off!" Dad said.

"What is a 30% discount?" I asked.

“Discount means that ordinary people have a bargaining mentality when buying things. In order to satisfy consumers’ psychology and achieve the purpose of promotion, merchants reduce the price of goods and increase the percentage of the original price of goods. You can think of it as dividing the original price into ten parts and giving a discount of 30%, that is, if an item costs ten yuan, then you only pay seven yuan. Okay." Dad said.

"Oh, that's it, then a 50% discount means paying five yuan, and a 40% discount means paying six yuan!" I said.

"Yes, now to test whether you really understand the meaning of discount, I will give you a question. The original price of an item is sixteen yuan. Now it is discounted for 40%. How much does it cost?" Dad asked.

I thought seriously: the original price is sixteen yuan, divided into ten parts, one part is one yuan and six cents, multiplied by six, it equals nine yuan and six cents. So, I answered loudly: "It will cost nine yuan and six cents after a 40% discount."

"That's right, Mingming is awesome!" Dad said happily.

I am very happy today because I understand the meaning of price discount and learned new knowledge.

Wang Ge's Mathematics Diary

(1)

There is a Shaobing shop near my home. When I bought Shaobing, I saw that it takes 7 minutes to process one pot of Shaobing. , a pot of sesame seed cakes is 7×5=35, you can buy 4 for one yuan, each is 25 cents, a pot of 35×25=875 cents, only 8.75 yuan. A pizza costs 60 yuan, which can buy about 60÷9≈6 pots of biscuits, which equals 6×35=210 biscuits!

(2)

Today, my mother went shopping at the "New Century" shopping mall. When she came back, she bought me two pairs of Shanshan pants and a Balabala top. Mom told me the price and asked me to calculate it.

Clothes

Original price (yuan)

Current price (yuan)

Trousers

138

25

Shorts

96

25

Top tops

78

< p> 39

Total

312

89

What a bargain!

We analyzed it: The reason for Balabala’s discount is that autumn is here, and if you don’t buy summer clothes, you will miss the opportunity. Although Shanshan's clothes are heavily discounted, the manufacturer is selling them for clearance.

Wang Jianai's Mathematics Diary

(1) Cutting watermelon

Today, my father and I met Zhao Linzhe and her father while playing in Congtai Park. So my dad asked them to go to my house and eat a big watermelon. When my father was cutting the watermelon, he gave me a difficult problem: How to cut it into nine pieces with four cuts, and leave ten pieces of skin after eating.

No matter how much I tried to cut, I could only cut out eight pieces, but I couldn't cut out nine. Later Dad told us the answer. Dad said: "Cut the watermelon twice horizontally and twice vertically to make a tic-tac-toe." The piece in the middle of the tic-tac-toe has skin on both sides, so after eating, there will be ten pieces of skin left. Do you understand?

(2) Divide the watermelon

When we finished cutting the watermelon and eating the watermelon, Uncle Zhao said: "Can I ask everyone a question?" We all said "Okay" Uncle Zhao Said: "I am asking a math problem. A group of people are dividing watermelons. If each person is divided into two watermelons, there are five watermelons left.

How about each person is divided into four watermelons? Three watermelons are not enough. Ask a** *How many people are there?

I know this is a problem of profit and loss. According to the formula "total number of people allocated = total profit and loss ÷ difference between the two allocations", it is calculated that there are four people in one.

Formula: (5+3)÷(4-2)=4

Wang Xinran’s Mathematics Diary

Mathematics Diary

——Calculate carefully Rental

I spent this summer vacation in Beijing. On a sunny Sunday, my mother and father took me to see a large-scale fairy tale puppet show - "Andersen's Journey"

While walking on the road, my mother said: "The China Children's Art Theater is too far away from our home. We can't walk to see the show. If we walk, don't talk about me, even you smart people can't get there. I'm so tired that my legs are broken. "

Dad said: "Let's take a taxi. "

Mom immediately said: "It is 30 kilometers from here to the China Children's Art Theater. The starting price of a taxi is 10 yuan, including 3 kilometers. In the future, it will be 2 yuan per kilometer, but after 15 kilometers, it will be considered as a round trip, and the fare will be increased by 50%. In other words, after 15 kilometers, the unit price per kilometer will change from 2 yuan to 3 yuan, and a taxi will cost about 80 yuan. Too expensive.

I immediately came up with an idea: "Don't you want to save money? Then let's calculate it in another way. If we get off the car at 15 kilometers, don't we not have to pay more? "

Dad nodded approvingly and asked: "How much money can I save by this?"

I did the math in my head and said: "The cost of taking a taxi is : 30-3=27km, 27-15-3=15km, 15*3=45 yuan, 45+10=55 yuan, 15-3=12km, 12*2=24 yuan, 55+24=79 yuan. If we get off the car at 15 kilometers and change to another taxi, the cost of taking two taxis is: 30/2=15km, 15-3=12km, 12*2=24 yuan, 24+10 =34 yuan, 34*2=68 yuan, 79 is 11 yuan more than 68, we can save more than 10 yuan.

”

Dad said happily: “Okay, Xiaobao, if you can think of it, I will give you an ice cream as a reward when you get out of the car!” "

Mom said with admiration: "Xiaobao, it seems that I will have to learn mathematics from you in the future! "

I said humbly: "Nothing! Just use your brain more! ”

This is really a happy Sunday!

Mathematics Diary

——Buying clothes on a budget

Today, my mother is washing When I finished my clothes and was about to leave the bathroom, I accidentally got a hole in my coat from the faucet. Seeing that my mother had ruined her clothes and was feeling sad, I walked over and said, "The old ones won't go, and the new ones won't come. Come on, let's go buy new clothes. "With that said, I pulled my mother out the door. My mother had no choice but to take me to buy new clothes.

"Which big shopping mall should we go to? "I asked curiously.

"Let's go to the nearby Hualian Shopping Mall to take a look. I heard that there are recent activities. "

Seeing the huge poster of Hualian Shopping Mall from a distance, my mother said happily: "Look, you can get 20 yuan off the products here for 200 yuan. Let's go and take a look." "

After entering the mall, my mother took me straight to the women's clothing area on the fourth floor. She walked around three times before looking at a black coat with embroidery on it. The waiter told us that this dress was 568 Yuan, if you buy 2 books for 200 yuan, you can get 40 yuan off, and you only need to pay 528 yuan. When my mother was about to buy, I pulled her aside and whispered to her: "Last time we went to buy books, didn't we pass by Xidan Mall? ? I saw a poster there saying that all clothes there were 10% off. Probably cheaper! ”

In order to buy more affordable clothes, my mother and I happily went to Xidan Shopping Mall. Sure enough, the exact same clothes sold for 568-56.8=511.2 yuan after a 10% discount.

p>

After doing some mental calculation, I happily said: "528-511=17 yuan, a total of 17 yuan can be saved. Or save more money by directly discounting. ”

On the way home, my mother was wearing the newly bought clothes and kept praising me for growing up and being able to manage money carefully.

Zi Liang’s Mathematics Diary

< p>Mathematics Diary (1)

Dad and I were chatting in the living room. Dad said: "You have already learned about age. Let me ask you. I am 35 years old this year and you are 8 years old now. Then When was I 4 times your age? "I said: "It's a matter of age, but it's also a matter of time difference. You are 27 years older than me. You are 4 times as old as me, which is actually 3 times as old as me. When I am 9 years old, that is, one year later you will be my age. 4 times. Is it right? "Dad nodded and smiled happily.

Mathematics Diary (2)

In the morning, my mother and I went downstairs to exercise. Many trees were planted in front and behind the building. Mom said we should do math. How many trees are there? I said, "Okay." My mother said, "Listen, plant poplars and willows in the front and rear of the building. Plant one poplar tree every 6 meters, and plant 21 trees." A willow tree is planted every 5 meters behind the building. How many willow trees have been planted? "I thought about it, the number of trees is 21, the number of segment trees is 20, 20×6=120 meters, 120 divided by 5 divided by 1 plus one is the number of willow trees, which is 25 trees. My mother nodded after hearing this.

Xie Xinran’s Mathematics Diary

Sunday, July 15, 2007

Today, my aunt sent me 6 pieces of clothing, each of which is from Shantou. Bought in the store, and they are all expensive! A printed T-shirt is 75 yuan, a blue pajama is 88 yuan, a pair of white culottes is 78 yuan, a camisole is 55 yuan, a pair of medium pants is 88 yuan, and a cross-body backpack is 38 yuan. One yuan, and there is also 125 yuan for postage!

Let’s calculate how much it costs - ah, it’s 547 yuan per piece! My aunt is so kind to me, she bought me so many beautiful things! Clothes, thousands of mountains and rivers cannot separate our family ties!

Sunday, July 19, 2007

Today I heard that there is a serious water shortage in the northwest, and there is a lot of water in Huining County, Gansu Province! A person only takes a bath three times in his life: when he is born, when he gets married and when he dies.

How about yourself? In a year, you wash once every two days in the spring and 45 times every day in the summer. I wash once, and I wash 90 times; I wash once every two days, and I wash 45 times in autumn; I wash once every three days, and I wash 30 times in winter, I took 210 baths this year. That’s 70 times as many times as the people there. And I’m 9 years old now, and I’ve had 1890 baths, which is 630 times more than the people in Huining. Oh! It’s so painful for people living there! Give them free water once a month so that they can take a happy bath every month

Monday, July 27, 2007

Today, I and I We went to the bookstore to read together. My mother said that if there are good books, just buy them.

My mother read 6 books, which cost 12 yuan each. This book is three times the number of books my mother reads, but the average price is only 6 yuan per book. In this way, the price of each book my mother reads is twice as much as mine.

My mother *** saves. 72 yuan, I saved 108 yuan, and the two of us saved 180 yuan.

Ah, it’s really a great way to save money!

Friday, July 27, 2007

In the past few days, 28 of our second-grade classmates and parents formed a tour group to visit Qinhuangdao and Beidaihe. We booked a quadruple room in a hotel near the beach. 28 people needed to book 7 rooms. The accommodation fee per person per night is 40 yuan, a four-person room costs 160 yuan per day, and 7 rooms cost 1,120 yuan per day. We stayed in Beidaihe for 3 nights and the accommodation fee was 3360 yuan.

Tuesday, July 31, 2007

Our renting fee used to be 550 yuan per month. During this holiday, the renting fee in the community increased again, and the landlord gave us an increase. It became 700 yuan per month.

In the past, our annual rent was 6,600 yuan; now, the annual rent is 8,400 yuan. This year it is 1,800 yuan more expensive than before. It is too expensive!

Saturday, August 4, 2007

My mother and I competed in rope skipping. I jump 137 times per minute, and my mother jumps 185 times per minute. My mother jumps 48 times more than me. We danced for 15 minutes together. I danced 2055 times in 15 minutes, and my mother danced 2775 times. The two of us jumped 4830 times in 15 minutes. My mother jumped 720 times more than me in 15 minutes. It was really amazing!

Wednesday, August 8, 2007

Today, my father, mother, sister and I went to the ancient Shilong Scenic Area. The average speed of my father’s driving was 60 kilometers per hour, which is equivalent to 1 km/min, *** drove for 15 minutes. It can be calculated from this that it is 15 kilometers from my home to the ancient Shilong Scenic Area. If the average speed is 2 kilometers per minute, you can drive there in 7 minutes and 30 seconds.

Sunday, August 16, 2007

I read 12 books during the holiday, and there are 36 days from July 12 to August 16, which is exactly On average, I read a book every 3 days. Each book has an average of 120 pages, which means I read an average of 40 pages a day. Sometimes I read around 50 pages or 30 pages, but most of the time I read around 40 pages.

Monday, August 20, 2007

During the summer vacation, my mother and I went to Beidaihe for a trip. We spent 1,200 yuan on food, accommodation, and shopping for the four days in advance. After we met, we spent 1,700 yuan. We spent 400 yuan to go to Baiyangdian, 105 yuan to the Ancient Stone Dragon Scenic Area, and 3,405 yuan to travel this holiday. Oh, that’s a lot!

Friday, August 24, 2007

The math oral arithmetic question card *** has 125 pages, and the fraction part has 8 pages. You don’t need to do it. I *** have to do 117 pages. There are 55 days of vacation, and I can finish the oral arithmetic question card by doing an average of 2 pages a day. If I write 6 pages every day, it will only take 19 days to finish, and I will have 36 days left to write other assignments!

Zhao Linzhe’s Mathematics Diary

The weather was sunny on Friday, August 3, 2007

Dividing watermelons

Today, several classmates came to my house Do your homework. The weather was very hot, and Ma Linlin said: "I want to destroy your watermelons." I said: "Yes, but you can only eat it if you solve the math problem correctly." They said: "Okay! Please come up with the problem quickly. "One yuan per person, two yuan per person, how many pieces of watermelon are there?" As soon as I finished speaking, Ma Linlin replied: "3 people, 4 pieces of watermelon." "The answer is correct. How did you calculate it?" I asked. "(1+2)÷(2-1)=3 This is the number of people. 3×1+1=4. This calculates the number of watermelon pieces." Ma Linlin answered, and the other students were right. A few of us shared the watermelon and ate it. Mathematics is so interesting!

It rained heavily on Sunday, August 5, 2007

Today, my father took me to my grandma’s house. On the way, my dad and I played a game. I counted the number of telephone poles on the roadside, and my father kept time. When Dad said start, I started counting. When Dad said time was up, I stopped. I counted 13 telephone poles in one go, and my father timed it for 2 minutes. My father also told me that the distance between every two telephone poles was 20 meters, and asked me what the speed of the car was. I replied: "(13-1) × 20 is the distance we walked. Dividing the distance by the time of 2 minutes is the speed of our cycling. The answer is 120 meters per minute." Dad praised me: "You are so fast. , The little head is so smart.”

I’m so happy! I discovered that mathematics is all around us.