This paper will talk about my own experience from the characteristics of primary school mathematics, the age characteristics of students, and the application of multimedia in mathematics knowledge plates.
First, the subject characteristics of primary school mathematics
"Mathematics is the mother of all sciences" and "Mathematics is the gymnastics of thinking". It is a science that studies numbers and shapes, and it is everywhere.
The three characteristics of mathematics are preciseness, abstraction and wide application. There are still some differences between primary school mathematics and mathematics science in rigor. For example, the extension of some operation rules is obtained by default, not by strict deduction. However, if you want to learn mathematics well, you must not relax the requirements for rigor and ensure the scientific content. The abstraction of mathematics is manifested in the abstraction of spatial form and quantitative relationship. It shows a high degree of generality and symbolizes the concrete process. Of course, abstraction must be based on concreteness. Needless to say, mathematics is widely used. At present, a large number of life situations have been added to the mathematics textbooks in the compulsory education stage, just to cultivate students' ability to solve practical problems by applying mathematics. Among the above three characteristics, this paper focuses on its abstraction. It is precisely because of the abstraction of mathematical knowledge that there is room for new technology to play its role.
Second, the age characteristics of primary school students and the corresponding courseware making requirements.
The age characteristics of primary school students can be described in two stages:
First, in the lower grades (1-2, 3), students are curious, active and easy to imitate, and the intuition, concreteness and visualization of thinking are the same characteristics. Therefore, the courseware made by teachers should adapt to this learning period: first, it should be interesting, and second, it should be intuitive.
How can it be interesting and intuitive? This requires teachers to study not only the contents of teaching materials, but also the psychological needs of children of this age before class, and then collect and select materials of various images that students like. For example, in order to improve children's interest in learning, they can choose animated images such as Pleasant Goat and Big Big Big Wolf. In order to make students understand the arithmetic of "addition" and "subtraction", static sticks can be combined and divided into one point, and abstract mathematical knowledge will become vivid immediately, which will interest students and make the teaching effect obvious.
Second, in the third year of senior high school, with the gradual maturity of physical and mental development, students gradually transition from concrete thinking in images to abstract thinking, and their ability to think and operate independently is constantly improved. Can think from multiple angles. Because they are less bound by stereotypes and habits, mainly because of their different ways of thinking. Active thinking began to increase dramatically. Curiosity and creativity are growing.
According to the thinking characteristics of students of this age, if the courseware design is too naive, students will think that thinking is worthless. I think we should not only make the lower grades interesting and intuitive, but also pay attention to highlighting the thinking and exploration of courseware.
For example, multimedia is used to provide students with rich materials of perception and representation, courseware is used to present the thinking process, and courseware is used to turn abstraction into intuition, thus building a bridge from image thinking to abstraction.
Example: understanding of the circle.
To establish the concept of circle, teachers and students often use coins, clock faces and other physical objects. When I mentioned the subject characteristics of mathematics just now, I said that mathematics is a rigorous subject. The representation of these objects is not the exact reflection of the concept of circle in mathematics.
Mathematically, a circle refers to the locus of a point with a fixed point as the center and a fixed length as the radius. However, this accurate concept cannot be directly said in primary schools, which requires teachers to remove the non-essential things in the physical objects and extract their essence. How to present the courseware? The first step is to display coins, clock faces and other physical objects on the screen. In the second step, the computer can slowly hide the non-essential things to leave the shape of a circle, and students can pay attention to the essence of the circle by "blanking". Such courseware can make students' attention shift from non-essential things to essential things, so as to understand mathematical concepts more clearly and accurately.
Thirdly, in each teaching section, the standard arranges four aspects: number and algebra, figure and geometry, statistics and probability, synthesis and practice.
The use and production methods of these four aspects are briefly explained in the form of examples.
1, Numbers and Algebra
In the teaching of Number and Algebra, there are some concepts, such as "factor multiple" and "the meaning of equation", and some calculations, such as oral calculation. What auxiliary things can multimedia do?
(1) helps students understand arithmetic.
In the teaching of "9+ several" in senior one, rounding "ten" is the basic calculation method. In order to let students understand how this "ten" is formed, we can show students the process of moving "Facebook" by using the "action path" function of "adding effect" in PPT "custom animation", so that students can understand how to move one of the two faces into a circle. In order to deepen more arithmetic, in addition to the movement of pictures, we also cooperate with the transformation process of formulas to enhance perceptual cognition and deepen rational understanding.
(2) It can enrich the forms of oral arithmetic practice.
All grades in primary schools should pay enough attention to oral arithmetic practice. In most cases, oral arithmetic is a form of mental arithmetic notes, and oral arithmetic ability directly affects the speed and accuracy of students' problem solving. In the teaching process, the design of multimedia oral arithmetic exercises mainly has the following forms:
First, use PowerPoint to present the content of oral calculation statically, and let students look at the big screen to do oral calculation. The advantage is clear, much better than a small blackboard, and easier to make than oral cards.
Second, using PowerPoint to dynamically present the content of oral calculation, students concentrate, read the dynamic questions, work out the results in their minds and then write them down. This kind of PPT animation is not difficult to make, and its dynamic forms are diverse. There are many ways for you to choose from in the effect of adding custom animation. The advantage is that it can concentrate students' attention and improve their interest in mental arithmetic.
Third, show the content of dictation in the form of recording.
The first two kinds of oral calculation belong to the category of "visual calculation", and there is another kind of oral calculation exercise, that is, "listening and calculating" Listening and calculation are more demanding than visual calculation, and students need to pay more attention to ensure that they can hear the questions clearly. Hearing stimulation is sometimes stronger than vision, which requires students' mental arithmetic ability, and the practice effect will be better.
There are many multimedia recording devices, such as tapes and computers. Nowadays, students use a lot of English "point reading pen" functions, which can also be used in oral arithmetic teaching. Moreover, the recording method of "point reading pen" is very simple. As long as you use the "recording label" function of the "point reading pen", you can quickly record the oral calculation content, match it with the label after recording, and then use it in class. Students listen to the formula and write the numbers. If you can't do it once, you can listen to it twice. After listening, you can listen to the examination again. Teachers can learn about students' lectures and inspections through inspections. This kind of exercise is simple and effective.
(3) The function of "trigger" in 3)PPT can enrich the content of exercises or the form of answers.
Exercises are an indispensable part of mathematics classroom teaching, and students need to present their answers on the big screen after answering them. At this time, different animation functions are used, and the presentation forms are also different.
First of all, it is often used to present them in the order of topics. For example, after oral arithmetic practice, the answers are presented one by one in the order of the questions. You can use "fly in" or other "effects". You can use sounds, such as applause and ringtones, to express affirmation, praise or mistake. You can use graphics to express mistakes, such as "crying face". The disadvantage is that students can only answer in order, which is a bit boring. Students know what to do next. Some students are visually tired, distracted or don't listen to their classmates.
Secondly, you can also use the "trigger" function or other functions to achieve the effect of random presentation, and students can click to display the answers to any questions they want to say, thus improving the interest and challenge of the exercise.
For example, in the teaching of multiplication estimation, students have different calculation methods, such as estimation or accurate calculation, and the estimation methods are different. When preparing lessons, the teacher should make a good preset, put all the methods in order and keep them in mind. Students can click to show which method can highlight students' dominant position in learning. However, the exercise content or answers appear in a certain design order, which is easy to cause teachers to guide students' thinking and turn "manual irrigation" into "machine irrigation".
(4) Using multimedia courseware can break through the teaching difficulties.
Using multimedia to break through teaching difficulties can be said to be the main reason why most teachers are willing to use multimedia courseware. As mentioned above, mathematics knowledge is abstract, and the thinking characteristics of primary school students also determine that students have certain difficulties in understanding. If the teacher can design some clever animations, students can easily understand what they have learned. For example, in the teaching of the basic nature of fractions, how to make students understand the relationship between the basic nature of fractions and the "quotient invariance" of division, and how to change 4/ 12 into 4÷ 12 by using the method of "action path", so that students can vividly reproduce the relationship between fractions and division, and it is much easier for them to understand the qualitative change of two sexes. Another example is an improvement exercise after knowing the score: using the score to represent the shadow part, some students with weak abstract thinking ability find it difficult to understand why the shadow part is a quarter. At this time, PPT combines scattered shadows through rotation, so that students can see at a glance.
2, graphics and geometry
The new curriculum standard points out that students should be helped to establish the concept of space in the study of Graphics and Geometry. The concept of space refers to abstracting geometric figures according to the characteristics of objects and imagining the actual objects described according to the geometric figures; ... drawing graphics according to language description or imagination.
In the teaching of Graphics and Geometry, the operation of teaching AIDS and learning tools is very helpful for students to form the concept of space. Therefore, in teaching, teachers should strengthen students' hands-on operation. If there are conditions for students to operate by themselves, never demonstrate. If there are no conditions for students to operate by themselves, try to demonstrate with teaching AIDS. If there is no demonstration, multimedia can play a role. Putting multimedia in the third place here is not to belittle its role in the teaching of Graphics and Geometry, but to highlight its value.
(1) Create a problem scenario
Interest is the best teacher. Whether it is a junior or a senior, good problem scenarios can stimulate students' interest in learning. Mathematics textbooks of all grades are equipped with pictures, aiming at making students interested in what they have learned, but in the final analysis, these pictures are static, and different students have different understanding of the information contained in the pictures. Then, how to turn the still pictures in the textbook into vivid images and arouse students' interest? Multimedia courseware has great advantages in this respect. It can be an animation or a video, which can be described as "vivid". Students like this scene, and their interest in learning is naturally high. For example, in a round area, the scene of "horse chaos" was designed. Through the discussion of the horse's range of activities, this paper introduces the necessity of calculating the area of the circle, which is both informative and childlike.
For another example, when teaching a volume, there is a scene of "crows drinking water" in the textbook. Teachers can animate static pictures and let students think while watching them. Students like cartoons best. While watching cartoons, their life experiences stored in their minds are fully mobilized. When the teacher asked, "Why can crows drink water?" Sometimes, students can tell from their own experiences: because stones occupy space, they "squeeze" the water up, and initially feel the meaning of volume. From these two cases, we can see that students are more interested in dynamic situations, and it is easier to stimulate students' enthusiasm for learning and desire for inquiry, which fully embodies the advantages of multimedia courseware.
(2) It helps students to establish the concept of space.
The formation of space concept is the key content of geometry teaching, so what space concept needs to be established?
What about multimedia support? In my opinion, some inconvenient operations can be handled by multimedia technology. For example, cuboid surface expansion diagram, cylindrical surface expansion diagram, rectangle and right triangle are rotated to form space graphics. Some simple "custom animation methods" are used in the surface development diagram of a rectangular box, such as "appearance" when the picture enters and "gradient" when the picture exits. According to the different stages of cuboid surface development, we can see different shapes, and vividly show the whole development process with one advance and one retreat.
Intuitive and interesting.
Of course, we should also make this flow chart into multiple PPt, and get the animation effect by playing it. Such as a cylinder side development view.
What figure do you get after rotating the rectangle? This is a common problem among sixth graders. Students can hold a rectangular piece of paper in their hands and rotate around the length of the paper. However, due to the slow rotation speed, it is not easy to see the situation after rotation. They can only experience the cylindrical shape after rotation through imagination, but some students just can't imagine it. At this time, if you can make a PPT to show the process of rotation, you can help students build the shape formed after rotation in their brains.
(3) It is helpful to deduce the volume calculation formula.
This is the most fully used and effective part of PPT in geometry teaching, which deserves our attention. The derivation process of some graphic areas is not easy to be realized by physical operation. For example, in the process of deriving the area formula of a circle, a circle can be divided into four parts, eight parts and 16 parts on average, which can be demonstrated with physical teaching AIDS. But if it is divided into more parts, the operation of teaching AIDS will be more troublesome. More importantly, it is not easy for students to accept that the assembled graphics are rectangular, and it is only the teacher's wishful thinking to let students agree with their own views.
It is close to a rectangle, which students can't see and naturally may not think of. Through multimedia courseware, students can see this extreme idea. With the support of images, the establishment of students' spatial concept has a foundation.
Similarly, this method can also be used to derive the volume of a cylinder. (Demonstration) However, the derivation process of the formula of "cone volume" still allows students to operate well in practice, and so can the courseware, but the effect of the courseware is not necessarily convincing. In the teaching process of "circle", the demonstration effect of courseware is stronger than hands-on operation. Through practice, it is found that it is difficult for students to measure the circumference by rolling coins in class, which takes up a lot of time, and this time is not necessarily necessary. At this time, we can combine teaching with multimedia, which can save time and achieve better results.
3, statistics and probability, comprehensive exercises
The new curriculum standard points out that statistics and probability only need to classify simple survey data under the guidance of junior teachers. Senior students need to go through the process of data collection, sorting and analysis and master some simple data processing skills; Experience the equal possibility of an event and master the simple method of calculating the equal possibility.
The common manifestations of multimedia in this part of content teaching are: creating scenes, presenting data, showing the needs of activities, enriching practice forms and so on. Specifically, I think there are still many examples that can reflect the advantages of multimedia, such as the drawing of statistical charts, especially when teaching the drawing of polyline statistical charts, so that students can clearly feel the process of making polyline statistical charts through dynamic "drawing points" (even if there is sound) and connecting lines (using the method of erasing). (Demonstration) In addition, when teaching statistical knowledge, it is necessary to provide students with some information that is not in the textbook, and the role of multimedia will be more fully reflected.
"Synthesis and Practice" appears in every textbook. Judging from the actual teaching situation, teachers do not pay enough attention to this part of the content, and the problem lies in the difficulty in grasping its teaching content. The new curriculum standard points out that this part of the content is "a learning activity with problems as the carrier and students actively participating, and an important way to help students accumulate experience in mathematics activities." It is not difficult to understand from this sentence that the requirements of curriculum standards for teachers are still relatively high. In order for students to achieve this goal, teachers must be fully prepared. Multimedia can help teachers present the collected subject knowledge to students in an orderly and diverse way, guide students' activities and enrich their activities. For example, in the lesson of "Magic Mobius Belt", the teacher introduced more knowledge to the students by using sounds and pictures after carrying out rich activities, which enriched the connotation of mathematical games and achieved the teaching goal.
To sum up, multimedia should be used reasonably in mathematics classroom teaching, as a supplement and expansion of conventional teaching methods, give full play to its unique role, and can not be used unprincipled or at a low level (only playing the role of a wall chart or a small blackboard), so as to foster strengths and avoid weaknesses and strive to achieve ideal teaching results.