Math diary 1
20 1X year x month x day sunny day
Every time I go to Tomb-Sweeping Day, there will be a sea of people on the giant mountain, so some swindlers come up with some deceptive tricks, such as gambling on something on a plate. Prop is very simple, draw a big circle on a board, and fix a rotatable pointer in the center of the big circle with a nail. The great circle is divided into 24 equal squares, and the needles in the squares can rotate. The box says 1? 24 equal numbers have no value in singular cases, but almost all of them have value in even cases.
The gameplay is also very simple. Set the pointer to 1 first, then you dial the pointer again, and the pointer will start to rotate and finally stop in a grid. Then press the number marked on the grid where the pointer is located and dial the pointer again. N- 1 grid, where n is the number marked on the grid.
This is just a little math game. In fact, no matter which box you dial, you can only lose money, not make money. Because when the pointer turns to an odd cell, the number of cells dialed is odd-1= even, and odd+even is only equal to odd, so it is impossible to turn to an even cell and nothing valuable can be obtained. If the pointer turns to an even grid and the number of grids dialed is even-1= odd, and odd+even = odd, then you won't get anything of value.
Math diary in the second semester of the second grade of primary school.
20 1X year x month x day sunny day
I began to learn multiplication of ten digits this semester. At the sight of multiplication, my head is big and dizzy. But today's experience made me make up my mind to learn math well. Today is my birthday. My parents bought a lot of vegetables to celebrate my birthday. ? Chef, dad? Tie the bib and start cooking.
? Stop? ! Seeing that my father was quickly picking up the oil pan and pouring oil into it, I quickly shouted. Today, the aunt of the neighborhood Committee just issued an oil control bottle. Controlling edible oil can reduce the risk of diseases, especially the possibility of rich diseases. At my strong request, my father had to pour oil into the pot with an oil control bottle. Dad obviously couldn't adapt to cooking with an oil control bottle, so he fried a green vegetable and used nearly 50 grams of oil. There are three people in my family. How much oil can we use every day if each person's daily intake of edible oil does not exceed 25g?
3? 25=75 (grams)
? Our family can only use 75 grams of oil a day? When I worked out the amount of oil my family could use in a day, I told my father loudly. Now dad is confused. He has used 50 grams, with 25 grams left. How could he fry the following dishes?
Seemingly? Chef, dad? I'm going to be fired. The dishes cooked today are not delicious except green vegetables. But our whole family ate delicious food, because we started a healthy diet. What's more, I used the math knowledge I learned to help my father correct his bad cooking habits.
Math diary 3 in the second semester of the second grade of primary school
20 1X year x month x day sunny day
One day, I got up and opened the window to get some air. Right after I opened the window, I was so scared that I slammed the window. There are many bees flying around outside the window. It turns out that these bees have settled outside our air conditioner.
Through the window glass, I can see the bee's nest. I feel very strange after reading it. There are many small holes in the bee's nest, which are arranged regularly. A question mark flashed through my mind. Through the internet, I know that every hole is a beehive, and every beehive is a regular hexagon. The whole hive is like a cone. All obtuse angles on this cone are 109 degrees 28 and all acute angles are 70 degrees 32. Originally, less beeswax was used to build this beehive, so the bees did less work. Moreover, such a beehive is very stable, has good sealing performance and will not be blown by the wind.
On the internet, I also found mathematicians among animals: red-crowned cranes, corals and small ants. Red-crowned cranes always flock in the air? People? Glyph, this? People? The shape is always a degree-110 degree. If you don't believe me, you can film it and measure it with a protractor. Coral draws 365 circular lines on the body wall every year, which is exactly one every day. Ant, don't underestimate it, it is also a mathematician. Every time I go out to carry food, the number ratio of big ants to small ants is always 1: 10, and there is a big ant in it every 10.
Math diary 4 in the second semester of the second grade of primary school
20 1X year x month x day sunny day
On Sunday morning, my grandfather and I went to the pharmacy in the lotus pond and bought two boxes of pills, two boxes of medicine and a box of 22 yuan in 44 yuan. Grandpa gave her 50 yuan, and the clerk gave it to Grandpa 6 yuan. After I found the change, I calculated it with decimal addition and subtraction. Grandpa can also pay like this: 1. Give it to 40 yuan, the shop assistant, and then pay 5 yuan. The asking price is 1 yuan. 2. If Grandpa has change, he can pay 40 yuan first and then 4 yuan. By buying medicine with grandpa this time, I know that mathematics is closely related to our lives.
Another time, my sister and I went shopping in the supermarket. I bought a pack of beef jerky, a bottle of milk and a bottle of soda. 10 yuan. Zhao Lin bought a box of biscuits, a bottle of soda and a piece of 9 yuan money. We gave the shopkeeper 20 yuan money.
The shopkeeper gave us money from 2 yuan. When we were about to go home, Zhao Lin said? I also want to buy 10 bubble gum. ? I took out the money and found that the shopkeeper gave me 1 yuan. Let's go back and return the extra 1 yuan to him. The shopkeeper praised us as an honest boy, and our hearts were filled with joy.
Math diary 5 in the second semester of the second grade of primary school
20 1X year x month x day sunny day
Today is Friday, and the test paper has been handed out. When I saw the results, I couldn't believe my eyes, only 86 points short. I'm really ashamed and envious to see someone else get a score of 100. I wish I could get a score of 100. But I blame myself for being careless, and I also blame myself for suddenly having a stomachache before I finished checking the first half of the test paper. I really don't know what happened.
And I clearly found a problem wrong, but I didn't have time to correct it. The question is 4 points. If I add up the scores of this question, I can get 90 points. This exam taught me a lesson: don't eat anything except dinner before the exam.
And the check is to write quickly and carefully, don't write typos, or the right one will become wrong, and count it several times. Write the answer quickly and not carelessly, because there is still time to check later. I will work harder this month, because I will face a final exam instead of a quiz. I will definitely work hard and try my best to get better results in the exam.