Math diary in the fourth grade of primary school 1 20 1X year x month x day x week x sunny.
In the math interest class, Teacher Zhuang brought us an interesting topic:
During the Qianlong period of the Qing Dynasty, Emperor Qianlong traveled south of the Yangtze River and met an old man with a birthday boy.
Upon inquiry, the old birthday star 14 1 year-old, Emperor Qianlong gave the old man a couplet: flowers bloom again, plus March 7.
Emperor Qianlong asked his accompanying minister Ji Xiaolan to make a couplet, which was very difficult for him. His couplets are: Celebrate the ancient and the rare, celebrate the spring and autumn.
The teacher said: There is a math problem hidden in this couplet. Please calculate how old the old man is after listening to the teacher. Flower armor? It means 60 years old. Reopen? You mean two 60-year-olds. Sanqi? It means 2 1 year, and the first part is 60? 2+2 1= 14 1 year; Guxi means seventy years old. Shuangqing? It means two sevens. How many years? That means one more year, and the bottom line is 70? 2+ 1= 14 1 year. It turns out that there are also mathematical problems hidden in couplets!
In fact, as early as ancient China, literati often made couplets to recite things and compare things, and they were very good at embedding some numbers in couplets, which made couplets not only literary and interesting, but also informative.
The fourth grade of primary school math diary quality encyclopedia II 20 1X year X month X day X week X sunny.
On Saturday afternoon, when I finished my homework and had nothing to do, my mother gave me a question: Do you know the characteristics of multiples of 2? As soon as I heard it, I immediately replied: they are all even numbers. ? What are their characteristics? Mom asked again. ? Their units are all 0, 2, 4, 6 and 8. ? Mom said:? You are really something. Do you know the multiple of 4? Do you know the characteristics? This beats me.
So, I found some multiples of 4 and found that their units are also 0, 2, 4, 6, 8, so I told my mother this rule. But my mother casually said a number, which overturned my discovery. Mom told me to keep watching, but I couldn't find it left or right. My mother reminded me: Look at the last two digits of these figures. I observed these figures according to the tips my mother gave me, and suddenly it dawned on me.
The original multiple of 4 is characterized by the fact that the last two digits of a number are multiples of 4, and this number is multiples of 4. Then, I found some numbers to try, such as: 437, 37 divided by 4=9 1, according to the law, 437 is not a multiple of 4, and then I divided 437 by 4= 109 1, which conforms to this feature. I found another number, 1024, 24 divided by 4=6. I found that 1024 is a multiple of 4. I verified it again by division: 1024 divided by 4=256, so 1024 is a multiple of 4. I happily told my mother about this discovery, and my mother nodded with satisfaction.
I found this. Students might as well give it a try.
Math diary's quality encyclopedia in the fourth grade of primary school 3 20 1X year x month x day x week x sunny.
During May Day, my mother and I went to the mall to buy clothes, but I thought the price there was very strange. Buy 100 and get 100? Does that mean you don't need money?
Mom said:? Silly daughter, how can you not use money?
I said:? Because it says that if you buy 100, you get 100, which is 100- 100=0, so you don't need money! ?
Mom said:? So that's how you calculate it. If so, everything in the mall is free, and there are many guests coming, so the mall will lose a lot. ?
Mom also said that you only need 50 yuan to buy 100 and get 100, you know?
After listening to my mother's analysis, I still don't understand. Why? It seems that I still have to go to the shopping mall to make a serious investigation or consult Ceng Laoshi to see what she has, because I know there is still a lot of math knowledge I haven't understood yet.
With a happy mood, I came to the school and asked Ceng Laoshi a math problem. Ceng Laoshi said? In fact, some are above 100. For example,109,200, 189 or above?
The teacher said again:? Full 100 yuan gift 100 yuan coupon. Customers still have to pay enough money to give coupons, which is not as free as you said. ? Ceng Laoshi praised my questions and welcomed me to ask more questions in the future.
After reading the quality of the fourth grade of primary school, math diary Daquan will also read:
1. High-quality fourth-grade math diary
2. Four selected compositions of 300 words by math diary in the fourth grade of primary school.
3. Four 400-word compositions written by math diary in the fourth grade of primary school.