1. I took 10 today and went to the third floor of Trust-Mart to buy books. I searched and found a book "Myths and Legends". When I saw the cover, I knew there were many wonderful stories in it. I decided to buy it, but when I saw the price, I was shocked again. It turns out that this book is 1 1 yuan. Feel the money in my pocket when reading this book. I'm really embarrassed!

2. The assistant aunt saw my embarrassment and asked kindly, "What's the matter, little friend?" I said shyly, "I want to buy this book, but I don't have enough money." She asked again, "How much money did you bring?" "Cai 10 yuan." I said. Aunt smiled and said, "Look at the price tag, little friend. It also says' Book sales are discounted, all of them are 10% off'."

I asked, "What do you mean by' 10% discount'?" Aunt said: "It is to collect money at nine tenths of the pricing. For example, 10 yuan's books only accept 9 yuan." I calculated that this book is only 9.90 yuan. "Yes!" I thank my aunt again and again. I bought a satisfactory book today and learned knowledge. I'm so happy! ?

I saw a puzzling math problem tonight. The topic is: 37 students want to cross the river. There is an empty boat at the ferry that can only take five people. How many times must they cross the river with this boat at least? ? Careless people often ignore the "empty boat", that is, forget to have a gondola, so they can only take four people at a time. In this way, 37 people subtract one rowing classmate, leaving 36 students, 36 divided by 4 equals 9, and the classmate who worked as a boatman on the other side for the last time also landed 4, so it takes at least 9 trips.

Today, the teacher taught us a jigsaw puzzle, which consists of a parallelogram, a square and five triangles. ? In our daily life, we can't do without the basic plane graphics in the puzzle, which can spell out interesting graphics, such as trees, houses, little girls, kittens and so on. As long as we study hard and love to operate, puzzles can be useful and interesting.

5, September 26th, Sunday, sunny. Today, the weather is sunny, and my father took me fishing. Dad's fishing rod is 6 meters long, which is 600 centimeters. My fishing rod is relatively short, only 4 meters, which is 400 centimeters. Dad caught a lot of big fish, which was 35 cm long. And I only caught a few small fish about 10 cm. Although I am not as big as the fish my father caught, I am very happy today!

6. Monday, February 26th, sunny. You can see round things, cookies, balls, water coasters, and so on. This is like the decimal point I know today. This is my new math friend. It turns out that it is hidden in every corner of our lives. When you go to the supermarket, it is hidden on the price tag. Bread is 2.30 yuan and jam is 8.90 yuan. What are these decimal points for? Take out bread 230 yuan, jam 890 yuan, haha, this time you know its power.

On my way to school, I saw a shop open. There are two atmospheric flowers hanging on both sides of the shop, and the door in the middle has 12 big red flowers, which are made of red silk. Very beautiful. On both sides of the building, from top to bottom, there are also 29 colored cloth strips with four big characters, "Business is booming". I calculated that 2 plus 12 plus 29 equals 43. I'm glad I can work out the formula of continuous addition.

8. Today, my mother and I went shopping in the supermarket. My mother bought three toothbrushes, three bags of apples and a cabbage. A toothbrush 9 yuan, a bag of apples 8 yuan, a cabbage 3 yuan. When my mother paid, I said, "9 yuan 2= 18 (yuan), two toothbrushes 18 (yuan);" 3 yuan 2=6 (yuan), 2 cabbage 6 yuan; 8 yuan 3=24 (yuan) 3 bags of apples and 24 yuan; 18 yuan +6 yuan +24 yuan =48 yuan ". Mother out of 50 yuan, 50 yuan -48 yuan =2 (yuan) should be taken back to 2 yuan. Today I helped my mother figure out how much money to get back.

Today, my grandmother and I went to the store to buy daily necessities. I bought a bottle of shower gel 28 yuan first, then four pieces of soap and a piece of 3.5 yuan. When I went to check out, I calculated it. 42 yuan, I gave the cashier 100 yuan, and the cashier gave me 58 yuan. ? Formula: 28+4X3.5=42 (yuan); 100-42=58 (yuan)

10, June 8, Sunday, sunny. Today, we went shopping. We bought 2 Jin of cucumber, 1 Jin of tomato and 2 Jin of my favorite potato. On the way back, my father asked me, "There are just four cucumbers. There are three of us. My mother doesn't eat cucumbers. How many do we each eat? "

Recalling the division I learned before, I said, "4÷2=2, everyone eats two." Dad nodded, smiled and said, "You're right!" I am very happy today. Not only did I go shopping with my father, but I also counted them. That's great.

1 1. Today, I finished everything. I felt bored, so I went to measure the circumference of the TV. When I measured the circumference of the TV with a ruler, I found that the ruler was not long enough. I thought: What should I do? It suddenly occurred to me that what xu teacher taught me today, we can use lines to measure. With this in mind, I started to do it. I cut a long white line and began to measure. When I was about to finish measuring, I found that the line was not long enough, but I didn't want to cut it, so I thought, how can I make it simpler?

I went back to my room and picked up a book to read. After a while, I found a simpler method. Because my TV set is rectangular, which only takes up one length and one width. I picked up the thread and measured it. After a while, I measured it. One length and one width is 106 cm, but there are two lengths and widths, so 106 times 2 equals 2 12 cm.

It turns out that the circumference of my TV set is 2 12 cm. I know that when measuring the circumference of an object in the future, if you can think of a simple method, use a simple method.

12 was stumped by a math problem when I was doing the homework of the math interest group today: "A bunch of watermelons, half and half, half and less than half. How many watermelons are there in this pile?" This topic is to count the number of watermelons, but it has no figures, so many "half" can confuse me. I was so anxious that I shouted at my sister, "How to calculate this problem?" My sister stared at it for a while and said with a smile, "If you think about it carefully, you can draw a picture."

So, I suppose there are eight watermelons, and I draw eight watermelons on the paper. Therefore, one half (1) is less than the other half (2) 1. I think this is wrong. Later, when my eyes lit up, I took off half a watermelon, that is, four watermelons and a picture. "Half of the four watermelons are half watermelons, isn't it half less than half of this watermelon (1)?" I jumped for joy!

"Ha ha! I calculated that there are four watermelons in this pile! " ? Children, if you encounter such a problem when you are doing it, you can draw a picture according to the meaning of the problem. This is a good way!

Today, my father and I went to the bookstore to buy books. ? We came to the bookstore. I picked out a long-awaited book and went to the cashier. Dad said, "Your book 12.6 yuan, my book 16.3 yuan, I took three ballpoint pens, 1.5 yuan. How much is left in 50 yuan? If you guess right, the rest of the money can buy you ice cream. " I think: 50 minus 12.6 plus 16.3 plus 1.5 times 3 equals 16.6 yuan. I said, "16.6 yuan." "Well, this 16.6 yuan can buy you an ice cream."

Dad said brightly that when I came to the ice cream shop, my dad asked me again, "I bought two ice creams with 1.5 yuan and paid 16.6 yuan. How much money is left? " I think: simple, 16.6 minus 1.5 times 2 equals 13.6 yuan. I said, "There is 13.6 yuan left." Dad said, "Not bad! Not bad. " I said angrily, "You underestimate me. This is a topic for two years. If I can't even know these, am I still a fifth-grade student? " ? Mathematics is inseparable from life.

14, Mathematics is an important subject, which is closely related to our life. It can be seen how important it is to learn math well! ? There are still many episodes in learning math for me-in recent weeks, we have been learning how to divide by a number. Because of lack of experience, I don't know much. There are always mistakes when doing problems. My mother always teaches me when I am free, but my mind is still blank. I always feel that what my mother said is just something I don't understand.

Mother can't help me, so she has to let me do exercises by myself. My mother told me first: the division formula is like going down the stairs. If this number is not divisible by the divisor, move the second number down. If the following number is not divisor enough, write 0 directly in the place where the writer writes. What my mother said made me understand the mystery. Although there are still mistakes in doing the problem, I can correct them soon.

Understand the reasons for the split, let me understand the truth of life, do everything step by step like taking the stairs, down-to-earth, or you may make mistakes again and again!

15, I met another math problem today, and it took me a lot of effort to solve it. The topic is: there are 30 birds in two trees, and 4 birds fly away from the second tree first. At this time, tree A flew to tree B with three birds, and the birds on the two trees were just equal. How many birds are there in each tree?

As soon as I saw the topic, I knew it was a reduction problem, so I solved it by the method of reduction problem. But when I checked, I found something was wrong. I will do it again more seriously. I think there are as many as four missing, half of them are 13, and the restored B-tree is14; A tree is 16. The formula is: (30-4)÷2= 13 (only); 13-3+4= 14 (only); 30- 14= 16 (only).

The answers are: a tree 16 and b tree 14. ? By solving this problem, I understand that no matter what I do, I should be careful, otherwise, even if I master the solution to the problem, the result will be wrong.