( 1)

Today, I was engrossed in my paper, and a question stumped me: "There are three uncalibrated cups, A, B and C, with volumes of 10 ml, 7 ml and 3 ml respectively. Now cup A is full of water, with the help of cups B and B.

C cup, divide the level in the cup in half. "I racked my brains and thought hard, but I just couldn't figure it out. What should I do? Got it! Find dad! Hmm! He is a rare mathematical wizard. How can such a small KS be rare?

Pour him wine! With this in mind, I came to my father's bedroom. I went to my father's bedroom and handed the paper to my father without saying anything. My father understood, but to my surprise, my father only said "no" and said nothing.

Yao. How is that possible? I thought anxiously. At this time, my father saw me like this and said, "You can solve it with practice." He magically took out three cups of different sizes. Practice? All right! I barely drive.

I began to practice. I first filled Cup A with water, then poured the water from Cup A into Cup B, then poured it into Cup C, then poured it back into Cup A, and then poured the water from Cup B into Cup C. Now there is only one millilitre of water left in Cup B, and I saw that the practice was successful.

Half. I'm so happy. I pour the water from cup C back into cup A, then pour a millilitre of water from cup B into cup C, and then pour the water from cup A into cup C. Now there is 5 ml of water in cup B, and then pour the water from cup C back into cup A, so it is horizontal.

They were divided in half, and my father praised me. I also want to: it seems that "practice makes true knowledge" is true, and practice can really help us solve problems! (2)

This afternoon, with my mother's permission, I went out to have fun. When I walked to the school gate, I looked at the electric telescopic door and thought of a question: Why does the heavy-looking telescopic door open and close square?

Convenient? I came home with questions, hurried to the bookshelf and took out "100,000 Why-Math Volume". As soon as I took out my book, I began to look for this knowledge. "Many good things grind", I finally found it.

When I got the answer, it said, "Because retractable doors are made of diamonds or parallelograms." But I thought about it again: Why can only a rhombus or a parallelogram do it? So I continued to look down: it turned out to be a quadrangle

This figure is different from a triangle in nature. The shape of a quadrilateral with four sides of a certain length is not fixed. This property is called quadrilateral instability, which is also called easy deformation. Matchbox can be pressed without much effort.

Flat, that's why. I solved the math problem in my heart and felt much better.