The first chapter in the first quarter of the three-dimensional graphics in life 1 class (P2~P4)
Editor: Liu Yuqin
Teaching objectives:
1. Experience the process of abstracting geometric charts from the real world and feel the richness of the graphic world.
2. Understand cylinders, cones, cubes, cuboids, prisms, frustums and spheres in specific situations, and describe some of their characteristics in your own language.
Teaching emphasis: Understand cylinders, cones, cubes, cuboids, prisms, frustums and spheres in specific situations, and describe some of their characteristics in your own language.
Teaching difficulties: accurately describe some features of some geometric figures in your own language.
Teaching methods: observation, discussion and induction.
Teaching technology and teaching AIDS: geometric sketchpad, computer courseware, physical projection, physical teaching AIDS.
Activity preparation: 1. Let the students recall the geometric figures (three-dimensional figures) they learned in primary school: cylinders, cones, cubes, cuboids, prisms, frustums, spheres, etc. And show physics teaching AIDS and pictures on page 3, so that students can systematically recall the shapes of these geometric figures.
It is these basic figures that constitute our living space. This is a photo of a corner of the city.
Street view photos, what familiar geometric figures can you find from them? (real investment) leads to a new lesson-
Three-dimensional graphics in life (blackboard writing)
Teaching process:
1, the courseware shows some photos of buildings and some stamps (with architectural pictures), so that students can feel the three-dimensional sense.
Geometry is in our life. At the same time, let students observe what familiar geometric figures can be found in each picture (let students go to the stage to explain who can find the most and the most accurate, so as to cultivate students' good habit of careful observation and bold speech)
2. Show the picture (actual projection) on page 2 of the textbook, and ask students to observe carefully and answer what familiar geometric figures are there.
Cultivate students' agile observation.
3. Show the picture on page 3, let the students observe it carefully, then discuss it in groups, and then answer the following questions:
(1) Which objects in the picture above are similar in shape to cuboids and cubes?
(2) Which objects in the picture above are similar in shape to cylinders and cones?
(3) Please find the object similar to the pen container in the above picture.
(4) Please find the objects with similar shapes to the earth in the above picture.
4. The courseware shows the geometric perspective of cubes, cuboids, cylinders, cones, prisms, frustums and spheres.
Ask the students to describe the characteristics of these figures in their own words.
5. The courseware shows the prism and the cylinder, and discusses the similarities and differences between the two geometric figures in groups, so as to form a comprehensive understanding of the prism in group discussion and exchange.
6. Exercise: Talk about what objects in life are similar in shape to prisms, cylinders, cones and balls.
Pair in groups to see which group gives more examples. (For example, the hexagonal nut of a machine part is shaped like a prism, with a tea box at the beginning of the barrel and a cylinder at the beginning of the teacup. Some ice cream showers are shaped like cones, blue balls, soccer balls and so on. The lamp shade of the desk lamp is shaped like a frustum.
7. Exercise: Classify the following geometric breaks and explain the reasons.
Question: What did you learn in this class? What numbers do you know? Do you find that you are surrounded by mathematics?
Work:
1. Do it and think:
(1) Draw a circle with a radius of 5cm, and cut a sector from the circle (the sector is larger).
② Align the two radii of the sector and roll it into a geometric shape.
Can you tell what geometry this is?
2. Make a cube with a side length of 3 cm. (Note: Please keep it after completion)
Postscript of teaching:
Students are interested in three-dimensional characters in life, and the atmosphere is excellent. They can recognize cylinders, cones, cubes, cuboids, prisms and spheres and describe some of their characteristics in their own language. They can also list which objects in life belong to cylinders, cones, cubes, cuboids, prisms and spheres. By observing and comparing physical prisms and cylinders, we can tell their similarities and differences in our own language, but we can't classify geometry. Students don't know what to divide according to. Only by pointing out planes and curved surfaces or columns, vertebrae and spheres will most students learn to divide them.