(A) the application of Flash in mathematics classroom Some contents in junior high school mathematics are difficult to explain and communicate with traditional teaching methods. For example:
(1) An ant crawls around the cone at point A on the bottom circle of the cone, returns to point A, how to climb the nearest point, and unfolds the side of the cone with multimedia animation. Students will use the shortest line segment between two points to find out how to climb the nearest point. After this difficulty is broken, the following problems are readily solved.
(2) When talking about "changing fish", making a demonstration in the animation area with a computer can make students quickly change from the static picture of the textbook to the dynamic picture of the courseware. Combined with the teacher's explanation and teaching of the changing law, cognition can reach a deep understanding of "vertical change, horizontal change, vertical change and horizontal change" in the process of abstraction → concrete → abstraction. In the teaching of "translation transformation, rotation transformation and symmetry (flip) transformation", these three transformations can be made into animation courseware, which can be demonstrated when teaching the corresponding content, so as to achieve the effect of students' direct understanding and lay a solid foundation for the teaching of congruent triangles in the future.
(3) When talking about "the positional relationship between a straight line and a circle", with the help of computer-aided teaching, the animated picture of "the round sunset slowly sinks into the Yellow River" is displayed, thus showing the three positional relationships between a straight line and a circle. Students can master more skills by enjoying beautiful scenery and making bold guesses. At the same time, students feel that "mathematics is not everywhere in life", so they can actively find problems in life and solve them, so as to achieve the purpose of "learning with pleasure".
(4) Traditional teaching is often explained by physical situational activities such as cutting radish or plasticine, and as a result, most students still have a little knowledge. If students can understand that the cross section is triangular, square, trapezoidal and rectangular, it is hard for students to imagine that the cross section is pentagonal or hexagonal. I made a FLASH animation and showed it to the students on the spot with a computer. Through the demonstration, students can really feel the process of being cut. Students can not only see how to cut pentagons and hexagons with five faces and six faces, but also quickly understand why they can't cut heptagons. Assuming that the position of the plane changes, you can feel the shape of the section from different directions. This not only saves the teaching time and energy, but also makes students feel the novelty of the materials and resolves the doubts and difficulties in this section.
(II) Application of the Geometer's Sketchpad in Mathematics Classroom The biggest feature of the Geometer's Sketchpad is "dynamic", that is, you can drag any element (point, line and circle) on the graph with the mouse, while all the geometric relations given in advance (that is, the basic properties of the graph) remain unchanged.
(1) For "What quadrilateral is a quadrilateral formed by connecting the midpoints of any quadrilateral in turn?" ? Try to prove the solution of your conclusion. I instruct students to explore as follows: ① Drawing: Students use the "geometric sketchpad" to make arbitrary quadrilateral (four vertices can be dragged at will) and its midpoint quadrilateral; (2) Exploration: drag any vertex of the quadrilateral to change its shape, and the shape of the quadrilateral will also change; ③ Guess: What properties of the original quadrangle determine the shape of the midpoint quadrangle? ④ Verification summary. This will leave more room for students to think, let them solve problems on the basis of existing knowledge, and constantly find new problems and put forward new conclusions, which will help to cultivate students' reflective consciousness and problem-solving ability.
(2) The position relationship between circles can be said to be a lesson that can best reflect the advantages of information-based teaching. Traditional teaching methods, such as moving circular pieces of paper, using fixed courseware, or drawing and explaining by teachers, are not as operable as "geometry drawing board" courseware. We only need to measure the radius and center distance d of two circles in the courseware, and slowly move the circle 2 to the circle 1 when the circle 1 is not moving, and observe the relationship between the two circles and the center distance d in the process, so as to obtain the conditions that satisfy the position relationship between the two circles as outer circle, outer circle, intersecting circle, inner circle and inner circle. After that, you can change the relationship between the radii and positions of two circles, hide the distance between the centers and do a variable exercise to find the range of the distance between the centers. A courseware runs through the whole process of concepts, examples and exercises, which not only ensures the effectiveness of concept teaching, but also improves the amount of exercises and thinking in class, which can be described as killing two birds with one stone.
(3) Application of Spreadsheets in Mathematics Classroom We can instruct students to draw statistical charts with spreadsheets, such as investigating the number of programs that students like in a class and making fan-shaped statistical charts.
(1), investigate the number of people who like all kinds of programs and make statistics;
(2) Open Excel software, input data by column or row and select;
(3) Use the chart function of the software to open the chart wizard window;
(4) Select a pie chart among the standard chart types, and click Next to open the window;
(5) Select a column and click "Next" to open the window;
(6) Select "Percentage (P)" in "Data Label Inclusion" of "Data Label" and click "Finish" to make a pie chart.
Using spreadsheets can not only draw fan charts, but also draw other types of statistical charts, and can also help us find statistics such as mean, median, mode and variance. For example, when drawing function images to explore nature, the method of drawing points and connecting lines is generally adopted. The more points are drawn, the more accurate the function image is drawn. However, it is sometimes difficult to draw accurate images only by hand, and it is easy to solve this problem by using geometric sketchpad. For example, draw an image with y=5X-2, start the geometric sketchpad to draw a function image, and input the analytical formula of function y=5x-2, the computer will automatically draw an image, and students can easily summarize the properties through observation. Drawing software can not only help us draw function images, but also help us study the properties of function numbers.
In teaching practice, comparing the effects of making courseware with traditional teaching methods for many times, I feel that it plays an incomparable role in improving students' thinking ability, improving classroom effect and improving teaching efficiency, and truly achieves that "compulsory junior high school mathematics curriculum should fully reflect the foundation, popularization and development, so that mathematics education can be oriented to all students, everyone can learn valuable mathematics, and different people can get different mathematics."