1. math diary, Grade Three, 200 words.
A few days ago in math class, the teacher gave us an application problem, saying that the bird eggs in the world are ostrich eggs, and its eggs are 1300 grams. How much does the smallest egg weigh? I put a question mark in my mind. After surfing the Internet and reading books in various ways, I finally found the answer in the China Youth Encyclopedia: the smallest egg is a hummingbird egg, and the hummingbird mother lays 2~ 1 egg at a time, which is only the size of a bean, each weighing 0.5g About 200 hummingbird eggs are the size of an egg. Hummingbirds can fly out of the nest for food and start an independent outdoor life after living for about 20 days.
What interesting knowledge, it can not only learn, but also increase extracurricular knowledge. It really kills two birds with one stone.
2. math diary 200 words in the third grade of primary school.
Today, grandma bought a duck weighing two kilograms and spent 15 yuan, 7.5 yuan per kilogram. She also bought two potatoes and half a catty of pork. Vegetables cost two yuan a catty. Grandma bought a catty and a half and used 3 yuan. In the evening, grandma cooked potatoes, fried vegetables and stewed ducks. Divide the potatoes into five parts. My mother and I ate two-fifths and my grandmother, aunt and sister ate three-fifths. Grandma also boiled the soup and divided it into six parts. We drank four-sixths of the soup, and this score can be divided into about two-thirds. This score is also the simplest score. Mom told me to eat more soup dregs, because 15% of the nutrition is in the soup and 85% is in the soup dregs.
3. math diary 200 words in the third grade of primary school.
Today, my mother asked me to buy four lettuce and two yuan of tofu. When I arrived at the vegetable shop, I chose four lettuce, and then asked my grandmother to bring me two yuan of tofu. Then grandma told me lettuce, 3.9 yuan, tofu and 2.7 yuan. I worked out how much a * * * is worth. A * * * 6.6 yuan, she should call me 3.5 yuan. I went home smoothly after paying the money. After returning home, my parents praised the food I bought.
4. math diary 200 words in the third grade of primary school.
One weekend, my good friends from the yard came to my house to play. I was going to play a trick on her and say, "Let's play a game. Each of us can only shout 1, 2, 3, 4, 4. Whoever calls 32 first wins, I'll count. If you lose, you will be punished. I'll shout first, 2. " She thought for a moment and said, "No ... you already know the law. I'm going to lose anyway." Because 32-2=30, 30=5×6, 5= 1+4=2+3, as long as the sum of the number I shouted with her and the first number is 2, I can win. I wanted to use this rule, but I didn't expect it to be seen through by her.
5. math diary 200 words in the third grade of primary school.
Today, I learned what is vertical. Originally, two straight lines that intersect at right angles are perpendicular to each other. One of the straight lines is perpendicular to the other, and their intersection is called vertical foot. In addition, I will draw vertical lines and parallel lines. Draw a vertical line from a point outside the line, and the length of the line segment between this point and the vertical foot is the distance from this point to the line.
Well done! After these two classes, I gained a lot of knowledge.