It will be sunny on Sunday, September 26th.

Today, my mother and I went shopping. There are so many food stores on the street! My mother and I are dazzled. My mother started to pick, and she picked left, right, up and down. Finally, she finally picked a tomato that she thought was good in a vegetable shop. Tomatoes cost 2 yuan a catty. She bought 1 kg 9 Liang, and she gave the vegetable vendor 3 yuan. The vegetable seller gave my mother 1 point. She bought ribs again. The ribs are 5 yuan a catty, and she bought 2 Jin and 2 Liang. She gave it to 50 yuan, the sparerib seller, and 39 yuan, the sparerib seller. She bought potatoes again. Potatoes are 1 yuan 1 kg. She bought 3 Jin and 3 Liang. She gave them to a vegetable seller, 5 yuan, and gave her 1 Yuan 70. She bought bean sprouts again. These bean sprouts cost 65438 yuan. She bought five taels and gave them to the vegetable seller 1 yuan. The change is fifty cents. She bought ginger again. Ginger 2 yuan 1 kg. She bought 1 kg and a half, gave it to the ginger seller 10, and got 9 yuan change.

She spent 18.7 yuan on dinner.

Math diary, Grade Four, Book One, 300 words Two: math diary, Grade Four, Book One (287 words)

It will be sunny on Sunday, September 26th.

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.

Math diary, Grade Four, Book One, 300 words Three: math diary, Grade Four, Book One (295 words)

It will be sunny on Sunday, September 26th.

On Sunday, my father and I went shopping.

When we came to the place where tomatoes were sold, my father asked, "How much is it?" The boss said, "1 yuan 2 jiao 1 kg." "I'll buy 3 Jin." Dad said. The boss weighs 3 Jin. Dad asked me, "Do the math, how much is a * * *?" I think: Easy, 1.2 times 3, isn't it equal to 3.6 yuan! I readily replied, "3.6 yuan." Dad said humorously, "Congratulations, you got it right!" " After dad paid the money, he went to the place where vegetables were sold. He asked, "How much is this cabbage? 1 kg? " The female boss said, "1 50 yuan." Dad asked me again, "I bought 2 Jin." Now I have 5 yuan money. How much should the boss give me back? " I think: 1.5 times 2 equals 3 yuan, and 5 yuan minus 3 yuan equals 2 yuan. "I replied," Looking for 2 yuan. " Dad said, "Yes! "

Walking out of the market, I suddenly realized that mathematics is often used in my life.

Math diary, Grade Four, Book One, 300 words Four: math diary, Grade Four, Book One (299 words)

It will be sunny on Sunday, September 26th.

Today, my mother said to me, "Xue Fei, play a game with you!" " "I said," good! "

Mother brought a round cardboard and fixed a pointer in the center of the cardboard with a nail. The cardboard is divided into 24 squares on average, in which 1-24 is written respectively. "Mom, what are the rules of the game?" "The rules of the game are simple: when the pointer points to an odd or even cell, the next number must be added. Adding up to a singular number means I win, and adding up to a double number means you win. "

I played more than a dozen times in a row and lost every time. "Why is it always singular?" I asked my mother. Mom said, "Think for yourself!" So, I racked my brains and finally reminded me: odd+even = odd. Now I understand that if the pointer turns to the singular case, then adding the next number is an even number; If the pointer points to an even grid, the next number added is singular. Therefore, when the pointer points to any grid, the total number is singular.

Math diary, Grade Four, Book One, 300 words Five: math diary, Grade Four, Book One (420 words)

It will be sunny on Sunday, September 26th.

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 happily

When I arrived at the ice cream shop, my father asked me again, "I bought two ice creams with 1.5 yuan and paid 16.6 yuan. How much 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 don't know all this, am I still a fourth-grade student? "

Mathematics is inseparable from life.

Math diary, Grade Four, Book One, 300 words Six: math diary, Grade Four, Book One (303 words)

It will be sunny on Sunday, September 26th.

One sunny day, my parents took me to buy stationery. When I arrived at Qilu Stationery Store, I saw all kinds of book covers, including Miss Rabbit's, Pleasant Goat's and Big Big Wolf's, and Blue Bear's ... I looked at the price list: 5.00 yuan for small book covers and 6.00 yuan for large book covers, and I immediately took 5 small book covers and 4 large book covers. Walking, I saw a beautiful pencil case, each 6.00 yuan. Mom said, "There are several pencil cases, so I still want to buy them!" " ""just the last one! "I said imploringly." Well, just the last one! ""hmm! " Say that finish, I picked up the pencil case I picked and put it in the basket.

When I got to the cashier, my father said, "Let's calculate first. How much do these cost?" I counted: "5×5+6×4+6, hmm ... 25+24+6=55 yuan!" Mother handed 55 yuan to the shop assistant, and our family went home happily.