Today, my grandmother and I went to the market to buy food. Before we came to the fish stall, my grandmother bought a crucian carp and a 6.6 yuan one. My grandmother paid 7 yuan, who bought the food first and then handed it to him 1 point. I asked strangely, "Why did grandma give him 1 hair?" Grandma said, "Keep reading." I saw the grocer give grandma 50 cents. It suddenly dawned on me that 7-6.6=0.4 (yuan) =4 cents, so it was more troublesome to find 4 cents. But Grandma's method is relatively simple: 7+0. 1-6.6=0.5 yuan =5 cents, so you only need to find 1 50 cents, which is much more convenient in the transaction process.

Mathematics is everywhere in life, so I want to learn it well and apply what I have learned.

Diary 2: math diary, Grade Three, 200 words.

1Tuesday, October 27th, the weather is fine.

I remember once, in order to consolidate my understanding of rectangular squares, my mother specially asked a question: "Put two rectangles with a length of 8 cm and a width of 6 cm into a big rectangle. What is the circumference of this big rectangle? "

I took out a piece of draft paper and drew this picture first: the calculated circumference is: 4x8 = 32 (cm) 2x6 =12 (cm) 32+12 = 44 (cm). I immediately said to my mother, "I figured it out! Equal to 44 cm. " But mother said, "There is another way." So I drew a picture on the draft. Oh, you can spell it like this, but the circumference is different, 2× 8 =16 (cm) 4× 6 = 24 (cm)16+24 = 40 (cm).

My mother seems to say to me again, "Think hard!"

Diary 3: The Complete Collection of math diary in Grade Three.

It rains in April 1 Wednesday.

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 will 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. Originally, I wanted to take advantage of this rule, but I didn't expect to be seen through by her!

It seems that I have to strengthen my math knowledge!