Keywords: first grade of Chuangguan Mathematics Primary School

This article applies to: the first grade of primary school.

Composition source:

This composition (600 words) is about the first grade of primary school (600 words), and the title is "Mathematical Breakthrough (II)". Everyone is welcome to contribute.

Mathematical Breakthrough (2)

Chen Liang and Clever are chatting happily. Clever asked a lot of math questions, and Chen Liang answered them.

Chatting and chatting, we arrived at the Math Castle. The buildings here are very unique, such as triangles, rectangles, polygons, trapeziums ... Cleverly said with one voice: "This is the place where our Math King lives. We are the left and right prime ministers here, but if outsiders want to come in, they must first answer the math questions given by Uncle Men. As an old saying goes, our country certainly welcomes students who listen carefully in class. Liang Chen nodded and looked at the topic carefully. I just heard Chen Liang blurt out: "A cuboid and a cube have six faces, each face of a cube is the same, and the two opposite faces of a cuboid are the same. They all have 12 edges and 8 vertices. "

Uncle Men said, "Yes, it is. Please look at the second question. "

Let's take a look at cat's answer:

Master Wang wants to stick decorative strips on the edge of a rectangular wooden box with a length of 6 cm, a width of 3 cm and a height of 5 cm. How long will it take at least?

(6+3+5)×4

= 14×4

=56 Deutsche Mark

A: at least 56dm decorative strips are needed.

Uncle Men added: "Correct, please see the third question."

Cat thought for a moment and filled in the answer:

A rectangular carton, length10cm, width 8cm and height 5cm. How many square centimeters of cardboard does it take to make 100 such cartons?

10×8×2+8×5×2+ 10×5×2

= 160+80+ 100

=340(cm？ )

340× 100=34000(cm？ )

At least 34,000 centimeters? Cardboard.

Uncle Men spoke again: "Correct! Please answer the fourth question. "

What is the sum of the volumes of a cuboid whose length, width and height are 3, 6 and 8 respectively and a cube whose side length is 6 cm?

3×6×86×6×6

= 18×8=36×6

= 144(cm？ )=2 16(cm？ )

144+2 16=360(cm？ )

Is the total volume 360cm? .

Uncle Men said, "Congratulations, you got all four questions right! If you want to see the king, please answer one of my questions. "

Chen Liang said generously, "Just ask!"

Uncle Men said: "This question is very simple, there is no time to think, but it is also easy to make mistakes."

Cat calmly and leisurely said, "uncles, don't mention it. Please ask questions. "

"What is the commonly used unit of volume?"

Chen Liang said without thinking: "cubic centimeter, cubic decimeter, cubic meter."

When Uncle Door was moved by Cat's earnest study spirit, the door finally opened slowly, and Cat walked into the magnificent hall under the guidance of two guards. ......

Self-evaluation: the third unit is also completed! Come and have a look if you want to learn. I reviewed it myself this time! Want to know about Unit 4? Then watch the next issue (it may take a few days, because I haven't finished learning, haha)!

Thank you, sister Maruko, for the beautiful calendar!