Health: The third area of the parallelogram is 8 square meters.
Teacher: Yes, size flats are square.
Health 2: Please note that the high and the parallelogram Yeah is not wide rectangular.
Division : Is there any way to test whether an area as large as they do?
Teacher: Now there are two views, the majority that the area is as large as the students, individual students that a large rectangular area. in the end who is right then? you can not find a way out of these two graphics than the size of the area?
Teacher: Can you give based on the data graph area of a parallelogram find it? (courseware produced under the map unit: cm)
Teacher: Why High-equal?
Health: Just find the bottom and a corresponding high, we can calculate the area of a parallelogram are equal.
(c) the consolidation and development
divisions: the area of parallelogram formula can also use letters? Do you know how to express it? (student said, teacher writing on the blackboard)
other end high, so the area is equal.
students: four corners of the rectangle are right angles, Therefore, only along the high-cut into a rectangle can be.
Teacher:: rectangle and the original parallelogram What is the relationship?
divisions: the lesson we have recognized the parallelogram, the students what knowledge they have learned, who I remember.
Health: transformation The graphics are rectangular, I found a long rectangle that is the end of the parallelogram, the parallelogram is a rectangle of width high, so the area is a parallelogram by the end of high.
Health: I do not agree, because ... ...
Health: 2 9 = 18; 3 6 = 18.
students: because they are a set of parallel lines, the distances are equal, so high are equal,
students: not equal, because a wide, one narrow.
2, What do you gain?
Third, the teaching process:
(a), Practice
Teacher: Who come to talk about.
Teacher: The flat rectangular shape and the original quadrilateral What is the relationship between parts of it? students to carefully observe the (media shows the process of transformation: to find out the end of the high draw, cut, pan, and pieced together, transformed into a rectangle).
(show Courseware: The kid's confusion. dubbing: a rash of small goat knocked down to a rectangle into a parallelogram, the little goat discovered a problem, what is it then?)
3, compare area
(present the problem: the current and previous rectangular parallelogram whose area is greatly? )
Teacher: Why not an area of 54 square centimeters?
2, the media presentation
Health: Understanding the parallelogram high.
3, today, we cut and complement learning into a parallelogram space, I hope the students it applied to future learning in life to be really learning Zhiyong.
Teacher: The following to school with your own hands with, try the parallelogram into the graphics we have learned.
1, students independently explore the creation of a parallelogram area calculation method of the learning environment, through the practical operation, conjecture verification, and other forms of learning exchanges and discussions to derive the formula area of a parallelogram , and can use the formulas for the area of a parallelogram, to solve some real-life computing problems in the area.
Teacher: The following Which two large parallelogram? Why?
Teacher: Your graphics are transformed what? how you converted it? who boldly came to talk about.
Students: Yes 54 cm2.
Health 1: Yes, thank you for reminding, and now look like the high parallelogram shorter, so the area should be smaller.
Student: I was reading to know.
students: two groups were parallel to the edge of a quadrilateral is called a parallelogram.
division: small goat in the end found a problem? Do you want to know about it?
students: as big.
Teacher: Who said that once again the complete .
1. port count each of the following.
students: Why would a parallelogram it? area is changed what?
students: You can calculate the size of their area.
Teacher: Let's take a look. Here you can calculate it? (courseware production)
< p> (b) of the Exchange to report
Health: I think the rectangular area, the small size of the parallelogram.
2, through the operation, communication, observation, comparison, so that students can apply into thinking that seeking parallelogram area approach, students identify problems, ask questions, analyze and solve new problems, the development of student space concept.
Teacher: How did you know?
Teacher: The earlier study, now you can own up to solve the problem kid?
parallelogram area formula to understand the derivation and transformation of thought.
Teacher: Do you agree? Let us take a look. (courseware display)
MSN Spaces perfect move to the Sina blog!
Students: rectangle area = length width (Blackboard)
1, this class of what we have to study? (Blackboard issues : area of parallelogram)
a teaching goal
Teacher: Why do you cut, do not cut along the line of high-not?
Teacher: Do you find anything?
3, penetration into thinking, inspire students to explore issues, identify problems of taste, culture student's sense of innovation, awareness and practical application of math ability.
Health: The formula is s = ah
Second, the teaching emphasis, difficulty
Teacher: Now you can find out what the problem it?
Student: I was told the parents.
the area of parallelogram = base height
2 . Analysis of the exercise:
Health 1: equal, rectangular area is long by wide. parallelogram by the end of the area is high. the length and width did not change so the same.
Health: equal, because their end of the same high are equal. So the same area.
4, to solve the problem of small goat
Students: Yes rectangle, I cut down the high.
(group work, 4 pairs, then in the class report)
Health: The second area of the parallelogram is 20 square decimeter.
Teacher: The earlier students We know the formula for area of parallelogram, the following work together to solve specific practical problems.
Teacher: We derived through transformation of the area formula and the same books. the students are really something, will find their knowledge of mathematics.
Teacher: How to count it?
Teacher: Why, then, the area of parallelogram = base height, the formula is how come? this lesson, we focused to study the parallelogram area formula derivation?
(d) review and sum up
Health: I do not think 9 6 = 54 (square centimeters), as six centimeters higher than 9 cm to this end on this. If this high along the 6 cm cut makes up a rectangle, a rectangle is 6 centimeters long this high, wide rectangular This is not the end of 9 cm. so we can not use 9 6 = 54.
1, tissue conversation
students: the first area of a parallelogram is 12 square centimeters.
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