A trapezoid is a quadrilateral with only a set of parallel opposite sides. Parallel sides are called trapezoidal bottoms: the longer bottoms are called bottoms, and the shorter bottoms are called bottoms; The other two sides are called waist; The vertical section sandwiched between the two base sides is called the height of the trapezoid. The following is the draft of the primary school mathematics lecture of Trapezoidal Area that I collected and sorted out. Welcome everyone to learn from it, I hope it will help you.
Trapezoidal area, draft of primary school mathematics handout, 1 Teaching content: calculation of trapezoidal area. I will talk about it from the following four aspects: teaching materials, teaching methods, learning methods, teaching process and attending classes.
First of all, talk about textbooks.
Content analysis:
The arrangement of basic knowledge about geometry in primary school mathematics textbooks is characterized by the understanding of trapezoid, which defines the characteristics of trapezoid and the concepts of bottom and height. This textbook first arranges the calculation of parallelogram area and triangle area, and then arranges the study of "trapezoid area calculation" Therefore, in order to make students understand and master the calculation formula of trapezoidal area, we must apply the theory of transfer assimilation, and bring the new knowledge of the calculation formula of trapezoidal area into the original cognitive structure based on the area of parallelogram, the area of triangle and the bottom and height of trapezoid.
Based on the above understanding, according to the requirements of the syllabus, I have determined the following teaching objectives.
(2) Teaching objectives:
1, through the practical operation of learning tools, learn to use the experimental method of cut-and-fill method, use the learned area formula to derive the trapezoidal area formula, and use the trapezoidal area formula to solve simple practical problems.
2. Through operation, observation and comparison, the mathematical thinking methods of rotation, translation and transformation are infiltrated to cultivate students' ability of analysis, synthesis, abstraction and generalization.
(3) Teaching emphasis:
Find out and understand the area formula of trapezoid and use it correctly.
(5) Teaching difficulties:
Understand the derivation and derivation process of trapezoidal area formula.
Teaching AIDS: self-made courseware, parallelogram and trapezoid made of cardboard, scissors.
Learning tools: some trapeziums made of cardboard, scissors, triangles and rulers.
In order to achieve the above teaching objectives, highlight key points, solve difficulties, and give full play to the role of modern educational technology, multimedia is used to assist teaching, changing static into dynamic, integrating sound, shape and color, providing students with vivid, vivid and intuitive observation materials and stimulating their enthusiasm and initiative in learning.
Second, oral teaching methods
According to the above teaching objectives, teaching emphases and difficulties, I intend to adopt the following teaching methods.
1. Development migration principle. Using the law of migration, we should pay attention to changing from the old to the new, guide students to learn new knowledge on the basis of sorting out the old knowledge, and embody the teaching thought of "reviewing the old and knowing the new".
Draft of "Trapezoidal Area" in the second lecture of primary school mathematics I. Textbook:
1. Lecture content: Chapter 3, Section 3, Volume 8 of the textbook for five-year primary schools. [Mathematics Network more primary school mathematics handouts]
2. Brief analysis of the teaching material: the area calculation of trapezoid is taught on the basis of understanding the ladder, which is the basis for studying the area calculation of graphics in the future.
3. Teaching objectives:
(1), master the formula for calculating the area, and you can correctly calculate the area of the trapezoid.
(2) By observing and comparing graphs, students' spatial concepts are developed, and their abilities of analysis, synthesis, abstraction and generalization are cultivated.
4. Teaching emphases and difficulties:
Key points: trapezoidal area formula.
Difficulties: Skilled and correct application.
5, teaching AIDS: courseware, small blackboard
Learning tools: two triangles, two trapeziums.
Second, teaching:
In the design process of this course, I adopt target teaching. In this course, I adopt the following teaching methods.
1, explanation method: In the teaching of this course, the calculation of trapezoidal area is unfamiliar to students. I teach trapezoidal area calculation by learning (the area deduction process of triangles and parallelograms) to improve students' deduction ability.
2. Guided discovery method: organize teaching by talking and asking questions, and guide students to go deeper and deeper and actively acquire new knowledge.
3. Discussion method: Based on the calculation of trapezoidal area, the formula is the teaching focus of this class, and mastering it is the difficulty of this class. In order to highlight the key points, break through the difficulties, and enable students to digest and absorb the new knowledge learned in this class, I adopted the discussion method and the operation method, and learned from each other through discussion, which reflected the students' main role and stimulated their interest in learning.
4. Practice method: Practice from different angles in various forms, which not only stimulates students' interest in learning, but also ensures the consolidation of knowledge and the formation of skills.
Third, study law:
1, under the guidance of teachers, use the law of knowledge transfer to learn knowledge, so that students can initially understand the internal relationship between mathematical knowledge.
2. Inspired by the teacher, asking questions teaches students to observe and distinguish the laws between similar things. Through the analysis, cultivation, summary, induction and generalization of problems, through different forms of practice, students' judgment and adaptability are cultivated.
Fourth, the teaching process:
1, review and pave the way, but also promote migration: around the teaching objectives of this class, we arrange the following processes in teaching.
< 1 >, premise evaluation:
Teacher: What figures can be made with two identical trapezoids?
Health: parallelogram
In order to arouse students' old knowledge and promote migration, the spelling and calculation of parallelogram area were introduced at the beginning of class.
Teacher: What is the area formula of parallelogram?
Health: area of parallelogram = base × height
Calculate the area of parallelogram (show courseware 1)
Teacher: Look, the teacher divided the parallelogram into two identical figures. What figure is it?
Health: divided into two identical trapeziums.
Teacher: Today, we are going to learn the calculation of trapezoid area.
Blackboard writing: the area of trapezoid
【 Design Intention 】 This arrangement of teaching not only reviews old knowledge, but also lays a foundation for learning new knowledge.
2. Guide discovery and summarize.
(1) Through students' hands-on spelling and observation, we know that a parallelogram can be divided into two identical trapezoids, thus converting the calculation of trapezoid area into the calculation of learned parallelogram area.
(2) The teacher asked the students to observe the courseware and their own parallelogram, and the students began to discuss and communicate: What is the relationship between the area of two identical trapezoids and the area of parallelogram? What is the relationship between the upper bottom, lower bottom and height of two identical trapezoids and the bottom and height of a parallelogram? Summarize the trapezoid area formula. The students answered the teacher's blackboard: the area of trapezoid = (upper bottom+lower bottom) × height ÷2. The teacher explained that if A stands for the upper bottom of the trapezoid, B stands for the lower bottom and H stands for the height, how should the letter formula be written? The students answered, and the teacher gave an example to understand the cross-sectional area and told us what the topic told us. what do you think? Students answer group exercises to correct.
(3) In order to consolidate the calculation of trapezoidal area, students should do "doing" and practice collective correction, which will help students master the formula skillfully.
【 Design Intention 】 The purpose of this teaching session is to enable students to sum up the formula of trapezoidal area through the discussion and application of what they have learned before, so as to remember and calculate the area correctly on the basis of understanding the derivation process of trapezoidal formula.
3. Various forms of exercises.
1, do: (courseware)
2. The following is a cross-sectional view of the river dam. What is its area? (courseware)
3. Find the area of the lower trapezoid: (only calculate the formula, not count)
(1) Upper bottom 1.8 decimeter, lower bottom 4.6 decimeter and height 3 decimeter.
(2) The upper bottom is 32 cm, the lower bottom is 47 cm, and the height is 14 cm.
(3) The upper bottom is 4.2 decimeters, the lower bottom is 3.6 decimeters, and the height is 5 decimeters.
(4) Upper bottom 18m, lower bottom 26m and height 8.4m ..
4. Choice: (Fill in the serial number of the correct answer in brackets)
(1) Find the following area, and the correct formula is () (courseware).
a 、( 13+ 15)×7÷2
b 、( 13+ 15)×4÷2
c 、( 4+7)× 13÷2
d 、( 4+7)× 15÷2
(2) Trapezoidal grassland, the upper bottom is 75 meters, 20 meters shorter than the lower bottom and 25 meters higher. The correct formula for calculating its area is ().
a 、( 75+20)×25÷2
b 、( 75-25+75)×25÷2
c 、( 75+25+75)×20÷2
d 、( 75+20+75)×25÷2
5. The area of trapezoid is 120cm2. If the height is 6 cm, then the sum of its upper and lower bottom surfaces is () cm.
6. The area of the trapezoid is 70dm2, the upper bottom is 8dm, and the height is 4dm, so the lower bottom of the trapezoid is () dm.
7. Find the area of the following trapezoid: (Discuss by students themselves) (Courseware)
[Design Intention] The teaching purpose to be achieved in this session: (1) Memorize the trapezoid area formula and apply it in practice. (2) Develop the good habit of doing problems seriously and writing and drawing correctly.
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