There is a problem in today's math homework to weigh a pair of shoes. So I went to my mother and asked for a scale. Mom said she didn't have weighing scale. What shall we do? However, as the saying goes, "Nothing is difficult in the world". I think there must be a way. So, I used my clever brain and came up with a homemade balance.

I cut off the paper covers of the empty moon cake box piece by piece, brought transparent folding tape, folded one of the paper covers into a regular triangle and put it on the table. Another piece of paper is made into the left and right disks of the balance and placed on the triangle in a balanced way. Then find something with weight at home as a weight. For example, my mother bought toothpaste, lipstick and other items, including 120g, 40g, 18g, 3g. I'm very excited to say that the shoe activity has started. I put the shoes on the left side of the homemade balance and the "weight of goods" on the right side. It is best to balance the weight on both sides. Then the sum of the weights is the weight of my shoes. Exactly 86 grams. Hard work pays off! I finally finished my math homework. Mom praised me when she found out.

He also joked with me: "In ancient times, there was a clever Cao Chong as an elephant, but now there is a clever Han Han as a shoe!" Say that finish, everyone laughed. It turns out that there are "scales" everywhere in life!

Math diary, Grade Three, 300 words Two: math diary, Grade Three (235 words)

On Sunday, June 8, the weather will be fine.

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.

Math diary, Grade Three, 300 words Three: math diary, Grade Three (244 words)

In life, mathematics is everywhere. For example: buy food! Buy stationery! Measuring cloth, etc. , all need to use mathematics. This semester, the teacher taught a new knowledge, that is, the multiplication and division of decimals. This knowledge helps me a lot!

Last night, my mother went to buy oranges together. A kilo of oranges 1.8 yuan. My mother bought 4.5 kg and should pay 8. 1 yuan. But the clerk was careless and didn't know how to calculate it, so it became 9 yuan money. Fortunately, this semester, I used the knowledge of Protestantism, and after doing a calculation in my mind, I immediately corrected the salesman's mistake.

Not only did my aunt, the shop assistant, praise me for my cleverness and my ability to multiply and divide decimals in such a small city, but my mother also praised me for saving her 0.9 yuan on the way home, and the knowledge I learned can be applied in my life.

Math diary, Grade Three, 300 words Four: math diary, Grade Three (272 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!"

Math diary, Grade Three, 300 words five: math diary, Grade Three (2 17 words)

It will be sunny on Tuesday March 8th.

Tonight, my mother and I go shopping in the supermarket. When we bought everything, we were about to leave. I saw milk on the shelf, so I asked my mother to buy some milk, and my mother agreed. However, just a few steps later, I saw boxes of milk on the shelf. With the same brand and weight, there are 12 bottles in it, each box is 2 1.6 yuan. Should I buy a box or a bottle? I hesitated. Suddenly, my mind suddenly changed, so let's compare it. So, I began to count: if I buy 12 bottles of 2.5 yuan at the retail price, I will buy 30 yuan; Moreover, the whole case only sells 2 1.6 yuan, and there is no 8.4 yuan, so I decided to buy the whole case.