Math diary in the fourth grade winter vacation: 2 articles.

Yesterday, my grandma and I went to the drugstore and bought two boxes of pills-two boxes of stomach Shu Ning, one box of 52 yuan and one box of 26 yuan. Grandma gave her 100 yuan, and the shop assistant gave it to grandma 48 yuan. After I found the change, I calculated it with decimal addition and subtraction. Grandma can also pay like this: 1. Give it to 50 yuan, the shop assistant, and then give it to 10 yuan for 8 yuan. If grandma has change, she can pay 50 yuan first and then 2 yuan. By buying medicine with grandma this time, I know that mathematics is closely related to our lives.

Yesterday, I got 95 points in the math tutoring exam. I made a mistake in filling in the blanks and writing questions. The teacher reviewed the fill-in-the-blank questions for us before the exam. I didn't recite it carefully, but I remembered it carefully. I was thinking about something else when I recited it, and I didn't remember it at all. So when I took the exam, I couldn't remember it anyway, so I just filled in the numbers. I didn't see the meaning of the title clearly, so it was wrong to write "X" as "+". This grade, the first 1 question is because my attitude is not correct, and the second question is because I didn't review it carefully. I will definitely do these two things in the future, but I can't be careless. Teacher, I can't get satisfactory results in every exam. Since I took interesting math, I understand that the most important thing in learning math is understanding. It's no use just copying other people's answers. It's no use copying them. So I will listen carefully in the future and strive for excellent results.

Math diary —— A Preliminary Understanding of Scores

( 1)

Today, my family went to KFC in Longgang for a family meal.

When we get there, people are always crowded. We finally ordered good food and found a seat to sit down. Here comes the food. This is a sumptuous set meal. There are 12 drumsticks in it. I thought: how to divide it equally? Then I remembered the division of 12÷3=4. We each have four drumsticks. Later, I ate my mother's 1 chicken leg and my aunt's two chicken legs. My aunt said, "You can't eat this for free. I ask you, how much did you eat? " How many more servings do you have to eat before you can finish them all? "I thought about it and replied," I ate 7/ 12, and then I ate 5/ 12. I ate all of it. "Fortunately, I learned the knowledge of fractions and can answer the questions correctly.

(2)

Today, my mother gave me 10 yuan to go shopping in the supermarket. I bought a string of firecrackers 2/ 10, four lollipops/10, seven balloons 2/ 10, and finally a comb 4/ 10, a *. There is still one yuan left, and I have to pay it back to my mother.

When I got home, my mother ate 1/4 lollipops, my father ate 1/4 lollipops, I ate 1/4 lollipops, and I gave the other one to my brother Xiao Qiang next door. (Author: Xiao Enling)

(3)

Last week, we studied fractions. Fractions have numerator, denominator and fractional line, for example, 1/3, where 3 is denominator, 1 is numerator and the middle horizontal line is fractional line.

Scores are used in many places in life. For example, a book has thirty pages, and each page is 1/30 of a book. Fractions can also be used to add and subtract! For example, half plus half equals two, which is 1. Why is this happening? If you divide a cake into two parts, each part is 1/2 of the cake, and then put the two parts together, there are two parts 1/2, which is just a cake. When adding and subtracting fractions, if the denominator is the same, only the numerator is added, regardless of the denominator. And 2/2 of the numerator and denominator are the same, which is 1.

I also learned to compare the size of fractions. The teacher taught us the formula: numerator is the same as denominator, the fraction with large denominator is small, and the fraction with small denominator is large; Denominators are the same as numerators, with large numerator scores larger and small numerator scores smaller.

The teacher also reminded us that when writing scores, we usually write the fractional line first, indicating the average score, then the denominator and finally the numerator.

1。 This morning, my father and I watched the Olympic torch relay program in Shenzhen on the Internet. I saw many people holding big red flags and small red flags, shouting, Come on, China, Olympics, Beijing. Very lively. Dad said that there are 208 contestants in Shenzhen. Each runner ran 200 meters, and 208 runners finally reached the city gymnasium. Dad asked me, do you know how many meters they all ran? Can you work it out? I said yes, I thought about it and worked it out step by step with the addition I had learned. The final score is 4 1.600 meters. Dad was right after reading it. You are so clever. Dad said, do you know how many kilometers it is? Dad gave me a rule of 1000m = 1km, saying that you can figure it out according to this rule. The first time I made a mistake, but the second time, under the patient guidance of my father, I finally figured it out = 41km 600 m. Dad praised me that you were great. Finally, I told my father that I wanted to attend. My father said that you should study hard in the future. I said I would, and I would cheer for our motherland. I also want to take the Olympic torch. This morning, my father and I watched the Olympic torch relay program in Shenzhen on the Internet. I saw many people holding big red flags and small red flags, shouting, Come on, China, Olympics, Beijing. Very lively. Dad said that there are 208 contestants in Shenzhen. Each runner ran 200 meters, and 208 runners finally reached the city gymnasium. Dad asked me, do you know how many meters they all ran? Can you work it out? I said yes, I thought about it and worked it out step by step with the addition I had learned. The final score is 4 1.600 meters. Dad was right after reading it. You are so clever. Dad said, do you know how many kilometers it is? Dad gave me a rule of 1000m = 1km, saying that you can figure it out according to this rule. The first time I made a mistake, but the second time, under the patient guidance of my father, I finally figured it out = 41km 600 m. Dad praised me that you were great. Finally, I told my father that I wanted to attend. My father said that you should study hard in the future. I said I would, and I would cheer for our motherland. I also want to take the Olympic torch.

2。 Mathematical problems on the court

One day, my mother and I watched the sports channel together. I have learned a lot, such as: running requires timing, and you can see the knowledge of hours, minutes and seconds in mathematics in swimming competitions.

The track of track and field competition is also very knowledgeable. For example, when starting at 400 meters, the athletes are not at the same starting line, so they have knowledge of circumference in mathematics. Some games have scores, such as basketball, which is a comparative knowledge in mathematics. There will be many numbers in the competition. For example, the number of athletes is an integer and the number of shots will be accurate to the decimal point. In addition, the finals of 1/8 and 1/4 that we often hear are all scores. There are many names for the stadium, such as 200m, 100kg and so on. The results of some competitions need to be averaged, and both the knowledge of calculation and the knowledge of averaging are needed here. There are also some games that are very learned. For example: round robin, knockout. These will all involve the knowledge of combination in mathematics.