Reflections on the object of mathematics understanding and graphic teaching in primary schools: Grade one students have just been promoted from kindergarten children to primary school students. According to their age characteristics, their thinking mode is mainly image thinking. How to let children know the main graphics in life and abstract simple three-dimensional graphics from real objects? Some time before class, I made a lot of preparations. On weekdays, we should pay attention to collecting articles from our daily life as teaching AIDS, such as cuboid toothpaste boxes and medicine boxes, cuboid biscuit boxes and Rubik's cube boxes, cylindrical tea boxes and teacups. And draw mathematical models on the card, such as the three-dimensional structure diagram of cuboid, cylinder and sphere. At the same time, before class, let students collect relevant daily necessities and make learning tools as required. In teaching, I first show all kinds of graphics I have collected, so that children can identify them one by one, then let them pour out their school tools, try to put together what they think is the same shape, and then show the toothpaste box, so that children can understand its general shape characteristics, such as counting how many faces there are and which faces are the same size, so as to guide children to explore and understand in purposeful thinking, such as toothpaste box, which is composed of six faces. The opposite object with the same size is a cuboid, and then I will make a carton with a different size from the toothpaste box, so that children can observe and talk about the characteristics, strengthen their understanding of cuboids and learn to be flexible. Then, on the basis of children's understanding of cuboids, the abstract picture of cuboid model is pasted on the blackboard, which promotes children's understanding of cuboids from concrete perception to abstract rational understanding, and guides children to know cubes, cylinders and spheres in a similar way, so that children can find the similarities and differences between cuboids and cubes in activities such as watching, comparing, touching and speaking. We found the similarities and differences between cylinders and spheres, and intuitively perceived the characteristics that cuboids and cubes cannot roll, while cylinders and spheres can roll.
This class is well prepared, the classroom design is also in line with children's learning characteristics, and the whole class has a strong learning atmosphere, which makes me and my students feel very relaxed and happy. After class, I carefully recalled that the goal of this class has been achieved, but students feel that the excavation of teaching materials resources is not deep enough, and they should pay attention to the expansion and extension of knowledge. For example, we only pay attention to the breakthrough of knowledge points in teaching materials, and only pursue "seeking common ground". We have a unified understanding of three-dimensional graphics such as cuboids, cubes, cylinders and spheres, but we can't actually classify them into those graphics. For example, figures like cuboids should be distinguished from cylinders and spheres. There is also a special cuboid with two square faces. Some children may mistake it for a cube, but it actually belongs to a cuboid. Children should compare the characteristics of cuboids and cubes, so that it is easy to distinguish them.
This lesson is children's initial contact with simple three-dimensional geometric figures, and the next lesson is to let students explore how to abstract simple plane figures from three dimensions. The "triangle" will be abstracted from the "triangular pyramid" three-dimensional figure. It seems that when we understand the three-dimensional figure, we should also supplement our understanding of the "triangular pyramid" and know that it is also a three-dimensional figure, so as to make full preparations for understanding the "triangle" of the plane figure later.
After reflection, when I was teaching "Understanding Plane Graphics", I began to ask questions, solve the problems left over from last class, make up for the lack of knowledge, further improve children's understanding of simple three-dimensional graphics, and pave the way for this class's "Understanding Simple Plane Graphics". This course makes children feel the joy of exploring knowledge and cultivates their divergent thinking, divergent thinking and dialectical analysis ability.