Teaching purpose:
1. stimulate interest, 2. Guide students to discover the calculation formula of rectangular area through experiments, 3. Make students understand the calculation method of rectangular area preliminarily; 4. Use the formula to correctly calculate the rectangular area.
5. Cultivate students' ability to ask, analyze and solve problems through teaching. 6. Teaching of infiltration experiment-discovery-verification learning method, 7. Give full play to the nature of students, 8. It lays a foundation for studying the calculation of other plane graphic areas in the future. 9. Educate students to love the motherland and science.
Teaching emphasis: understand and master the calculation formula of rectangular area.
Teaching difficulty: guide students to get the formula of rectangular area through experimental exploration.
Teaching structure: the teaching mode structure of "independent inquiry" is adopted.
Teaching assumption: stimulate interest, induce learning motivation and cultivate the spirit of active exploration. Highlight the foundation and development of mathematics teaching, and realize that everyone can learn valuable mathematics, everyone can get the necessary mathematics, and different people can get different basic teaching concepts of development in mathematics.
Teaching AIDS: rectangle, red flag, courseware, etc.
Learning tools: learning paper, ruler, 1 cm2.
teaching process
First, the creation of situational import
1. courseware shows the structural diagram of the new house, questioning:
2. Show a square of 4dm×2dm. Which area is more suitable? How to measure with a small square of 1 square decimeter? Compare the two swing modes.
3. Title introduction: Our great motherland is full of rivers. Who knows how big our country is? What is the area of Wuhan? What is the area of our Guanshan primary school? Is it appropriate to measure one by one with area units?
4. What do you want to know after reading the topic?
According to the students' answers, the teacher summed up: What is the calculation method of rectangular area? Courseware tips.
Teacher: In this class, we will study around this question raised by our classmates. I hope everyone can use their brains, use them in groups and solve them together.
Second, practice and explore to find methods.
(A) provide materials to inspire students to make bold guesses.
1, the courseware shows a rectangle 2 cm long and 1 cm wide.
2. Change the length and width of this rectangle through courseware to get four rectangles with different sizes, and guide students to observe the changes of graphics.
3. Question: If the length and width of a rectangle are constantly changing, how many rectangles with different sizes can be obtained?
4. Guess: Through the change of this rectangle, what do you think the area of the rectangle may be related to?
(2) Experiment in groups to find the calculation method.
1. Teacher's guidance: Does the area of a rectangle have anything to do with its length and width? We can do a little experiment.
2. Layout experiment requirements: Place any rectangle in the area unit of 1 cm2, find out the length, width and area of the rectangle you put, and record it.
3. Courseware shows the experimental report, each group of experiments, records the experimental results, and the teacher visits and guides.
4. After reporting the measurement results, input the experimental results of each group into the courseware at the scene. Each group leads the team members to carefully observe the form and actively discuss and think about the problem. (Observation experiment report)
Thinking: What is the relationship between the number of square centimeters contained in the rectangular area and the rectangle? What must they do?
5. Each group reported the results of the discussion and found that the square centimeters contained in the area of a rectangle are exactly equal to the product of the centimeters contained in the length and width.
6. Guide students to discover the method (the formula for calculating the rectangular area) and encourage them enthusiastically.
(3) Classification verification and confirmation of calculation methods.
1. Leading question: Is this finding accurate? Is this method suitable for calculating the area of all rectangles? We still need to verify this discovery.
2. Layout verification requirements and verification methods are discussed. Students independently verify and exchange verification results.
Third, sort out the summary and prompt the learning methods.
1, Question: After learning this, do you know the calculation method of the area of a rectangle? How did we find this calculation method?
2. Induction: experiment-discovery-verification. Infiltrate the education of learning scientific methods.
Fourth, the application is widely known and consolidated.
1. Calculate the area of a rectangle with a formula.
2. Apply formulas to solve practical problems in life.
Students want to measure the area of some hidden rectangles around us? Two students at the same table cooperate to find a rectangular surface and measure it. Record the results on paper when measuring.
Play music for students to measure, and then exchange the measurement results in each group.
(1) Back to the import problem. The courseware shows the structural diagram of the new house, gives the data, and asks students to calculate the area of each part of the new house.
(2) Courseware shows pictures of broken mirrors, gives data and allows students to calculate the length.
Verb (abbreviation of verb) deepens and expands.
What are your plans after learning this method?
6. Open question: The courseware shows a design drawing to stimulate students' creative enthusiasm. Please be a designer to design a new school plan for our Guanshan Primary School.