Teaching content: experimental textbook for fifth grade of compulsory education curriculum standard published by People's Education Press, 80-8 1 page.

Teaching objectives:

1. The parallelogram is transformed into a rectangle with constant area by cutting and filling method, and the calculation method of parallelogram area is deduced by the calculation method of rectangular area.

2. Simple practical problems can be solved by calculating the area of parallelogram.

3. Infiltrate and transform thinking methods in operation, observation and comparison.

4. Experience the happiness of success in inquiry activities.

Teaching emphasis: Derive the parallelogram area formula and use it to solve simple practical problems.

Teaching difficulty: Deriving parallelogram area formula

Teaching preparation: courseware parallelogram cardboard scissors transparent square paper

Teaching process:

First of all, the situation is exciting:

Teacher: Students, have you ever been to Jiang Bin Park in ningjiang district? Is it beautiful? The park will also pave the lawn here. These are two of them (the computer shows the lawn map). According to the mathematical information provided in the picture, what mathematical questions can you ask?

1. How much does it cost to pave a rectangular lawn? (According to the rectangular area formula, students can solve it) 2. How much does it cost to pave a parallelogram lawn? Teacher: What do you need to ask first?

Health: the area of parallelogram. Teacher: In this class, we will learn the area of parallelogram. (blackboard writing topic)

Second, experimental exploration:

1, guess

Then guess what the area of the parallelogram may be related to. (Maybe it's related to the edge) Only related to the length of its edge? Look at this parallelogram in the teacher's hand. (Demonstration) What else can it be related to? (Height) So what is the relationship between the area of a parallelogram and its base and height? Let's study it together.

Step 2 experiment

1) Independent query:

Teacher: There are some learning tools on the desks of each group, including grid paper for calculating grids, printed parallelograms and rectangles, desks, scissors and parallelograms. Think about how you plan to study them.

Health: I count squares.

Teacher: When counting grids, if it is less than one grid, count it as one grid and fill the data in the table.

Teacher: Is there any other way?

Health: I used the method of cutting and spelling.

Teacher: Please read the instructions of the students who use the cutting and spelling methods. (lifelong reading) Here, you can try it in the way you like.

2) Intra-group communication:

Teacher: Who gets what by counting squares or cutting and spelling? Communicate your ideas in the group, and the group leader will organize them. You will report your group's methods to the class later.

3) Student report:

The first group: (1) counting grids (bring the table to the front)

(2) Cutting and assembling

Teacher: You have successfully turned the parallelogram into a rectangle. What is the relationship between this rectangle and the original parallelogram? (health: the length of a rectangle is equal to the base of a parallelogram, and the width is equal to the height of the parallelogram. The transformation of your group is very clear, and the introduction is really great. )

Is that so? The demonstration and explanation of teachers' courseware emphasize translation.

Teacher: Are there any other ways to cut and paste? The method of your group is different from others, which makes the students learn another trick! The students report the demonstration to the teacher.

What a clever cut. I find your thinking very flexible. I can only say two words: "admire!" )

Teacher: Is there any other way? Students in other groups, what conclusions have you drawn through hands-on operation? Say it together (blackboard writing: area of parallelogram = bottom * height)

Teacher: If S is used to represent the area of parallelogram, A is used to represent the base of parallelogram, and H is used to represent the height of parallelogram, how to write the area formula of parallelogram? S = ah

Fourth, use the formula to solve.

Teacher: Now let's figure out how much it will cost to pave this parallelogram lawn.

(oral calculation)

Verb (abbreviation of verb) expansion exercise

1. What is the area of the picture below?

Base 15cm, height 1 1cm.

Not only did you work out the exact result, but it was also very fast, which was really good. )

2. Title: This is a map of the whole country. The terrain of a province is very close to parallelogram, Shanxi Province. Shanxi is about 590 kilometers long from north to south and about 3 10 kilometers long from east to west. Can you estimate its land area? (Can things be a little smoother? )

It's great to use formulas properly when solving practical problems.

3. The school wants to build a parallelogram flower bed with an area of12m2. Please help the school design it. (The bottom and height should be the whole meter) 1) How many schemes can there be? 2) Which scheme is more reasonable? We can consider it from different angles and choose a more reasonable scheme for the school. Thank you very much, teacher.

The class summary of intransitive verbs:

Teacher: How do you study this course? What have you gained?

(I use the method of square number, and I use the method of translation. I convert the parallelogram into a rectangle and compare it with the parallelogram to get the area of the parallelogram. You are great. You can find a way to convert the parallelogram into the rectangle we learned before to study its area. The method we use in this class will be used in other graphics fields in the future. Today's assignment is to write a math diary on the topic of "parallelogram area", and describe the derivation process of parallelogram area clearly. You can draw or cut and paste.