Hua, a famous mathematician, said: "The universe is big, the particles are tiny, the speed of rockets, the cleverness of chemical engineering, the change of the earth, the complexity of biological mysteries, and mathematics is everywhere." Especially in 2 1 century, the application of mathematics is everywhere. Then, how can we lay a good foundation in mathematics from an early age, and what kind of classroom teaching is suitable for the new generation of students? In my opinion, it is our wish that students play a leading role in classroom learning. Then, math activity class is a teaching method that allows us to fully embody autonomous learning.
In the activity class, we are divided into groups under the guidance of the teacher, and through measuring, piecing together, cutting and calculating by ourselves, we explore the law of discovery and master mathematical knowledge. This not only cultivates the practical ability, but also improves the thinking ability, which gives us a preliminary taste of the success of mathematicians in studying problems and doubles our interest in mathematics.
For example, in our "Calculation of parallelogram area" class, the teacher asked us to divide into several groups and hand out some small pieces of parallelogram paper for the students to discuss with each other. How to make a parallelogram into a figure whose area we have calculated? Everyone had a heated discussion. Some students found that parallelogram can be cut into right triangle and right trapezoid along its height with scissors, and then it can be spliced into rectangle. Some students also found that two right-angled trapezoids can be cut from any height of a parallelogram and can still be combined into a rectangle with the same size. Through observation and thinking, students realize that the "length" and "width" of the combined rectangle are the "bottom" and "height" of the original parallelogram respectively. So, everyone finally found the parallelogram area formula: S=ah. The teacher asked the students to play poker, so that everyone could quickly understand and master the calculation law of division with remainder and learn knowledge in relaxed and happy activities.
Every time I do math olympiad, I always pick up a problem to do it, because I think it will be done quickly. However, doing math olympiad today, a problem changed my view. It is not necessarily right to do it quickly, but mainly to do it right.
Today, I made a question that puzzled me. I struggled for hours and couldn't figure it out, so I had to obediently read the basic extraction and let it help me analyze it. The question is this: How many odd numbers are there in the square of 333333333? The analysis is as follows: the square of 33333333333 is 333333× 3333333. Because there are too many numbers, this multiplication formula is very complicated. We can simplify it by transformation, that is, one factor is enlarged three times and the other factor is reduced three times. The product remains the same. The problem turned into finding 99999999999×1111111= (65438 438+0 1 1 1 1 = 1 1 1 1 1 1 1 1 1 1 1 / Kloc-0/10000000-65433833× 33 =1089 → There are two odd numbers in the product; 333× 333 = 1 10889.
From the previous calculation, it is easy to find that the product consists of four numbers: 1, 0, 8 and 9. The number of 1 and 8 is the same, which is less than the number of 3 in a factor 1, and 0 and 9 are after 1 and 8 respectively. The number of odd numbers in a product is the same as the number of 3 in a factor. It can be deduced that the product of the original problem is:111110888889, and there are10 odd numbers in the product.
After finishing this problem, I know I can't do math and Olympics quickly. I need to know how to do it. In a word, I think it is very popular for us primary school students to have math classes in the form of activity classes. In class, every student is curious about the process of exploring knowledge and eager to find a solution to the problem through his own experimental activities. In learning, we fully realize the happiness and pride of the host who is learning. I hope teachers can take more math classes in the form of activity classes.