Teaching objectives of "comparison area" teaching plan 1 for large class mathematics;
1, several comparison methods of clearance area.
2. Learn to draw squares, measure the area by counting squares, and compare the size of the area.
3. Understand that patterns with the same area are not necessarily the same in shape, and have a preliminary understanding of conservation.
4. Cultivate children's comparative judgment ability.
5. Develop children's logical thinking ability.
Teaching preparation:
Various patterns, small squares
Teaching process:
First, straighten out the existing experience, compare the size of the area with various methods, and derive the concept of "area".
1, and the specific area is measured by visual inspection.
The teacher showed two patterns (green and blue) with very different sizes.
Teacher: "Which is the bigger of the two patterns?" (Child: "...") Teacher: "Oh, I found it with my eyes in an instant."
2, the superposition method is larger than the area, (the kindergarten teacher shows two pieces of paper with little difference in size)
Teacher: Which is bigger at present? Don't you agree with me? (Child: "The orange one is big, the white one is big ...), Teacher:" It looks quite equal. How can it be compared with the size? " (Child: "Add up")
Ask the children to come up and have a try.
Teacher: I think the corners on one side are all aligned one by one. What method did you use? This is called superposition method.
Teacher: Which is bigger? It's so big that it can be understood in an instant by superposition method.
Conclusion: When two patterns are basically incomparable in size, the superposition method is really a good method.
(Kindergarten teacher: Yes, when you can't see who is bigger, the superposition method is really a good method. )
3. Derive the concept of "area"
Teacher: By comparing the two groups just now, we know that the size of the pattern is big or small, and the size of the pattern has another name, which is the area of the pattern.
By comparison, it can be said that the area of green paper is larger than that of blue paper. The kindergarten teacher pointed to another group of 1 and asked: What does this group say? The child said, "The area of yellow paper is larger than that of white paper." .
4. Specific area of counting grid method
Kindergarten teachers show two random patterns (the same area)
Teacher: There are two patterns here, but the shapes are very strange. Which area is large? Is there (any) way to compare? Does the superposition method work?
Kindergarten teacher: "Don't worry, I brought tools today. What is this? It can help two patterns to measure the area and size.
How to measure? (The kindergarten teacher puts the pattern on the blackboard) Align the corners of the square with the corners of the pattern. 1. Draw the outline, then overlap the edge with the corner of the outline just now, and draw the outline one by one from left to right. Draw a line, measure and draw, measure and fill the whole pattern. In the future, use this small square to measure and fill the pattern of the number 2 in the same way.
Teacher: After measuring, do you understand who is older and who is younger? (Child: Same age) What do you mean? Use six squares to measure the pattern area of 1 and six squares to measure the pattern area of ②. So their area is the same.
Kindergarten teacher: How many squares did we use to count the pattern of 1? (The kindergarten teacher wrote it down while counting), and how many squares did we use to count the pattern of the number 2? So their area is the same.
(Kindergarten teacher's summary: It seems that although the pattern is different, the area will be the same. )
What method was used when it was just larger than the area? (child: orthographic painting), yes, we draw squares and count each grid, so we can call it counting grid method.
(Summary of kindergarten teachers: When two patterns with different shapes can't compare with the area, the counting grid method is really a good method. )
Second, the child hands-on operation
Teacher: The counting grid method is good. Do you want to have a try?
The 1 and 1 groups have 4 patterns, 4 squares and Gou Xianbi.
I have prepared a design and a small square for each of you, and put it in the basket on the table at the back. Understand the area of the pattern by grid drawing and record it. Please don't bring a small stool. Four people share a table. (After recording, put the small squares back in place, take the patterns back in place and see who sits.
(2) find your good partner to compare which area is larger; Which area is smaller than the other side?
Let the children come up: "Who did you compare with just now, then come up, which one of you has a large area and who has a small area?" Why is the pattern area not as big as your partner's? Why? Are they the same shape? Patterns that look the same size have different shapes. Who is in their district? Improve your design.
(3) At present, these patterns are all home, and the patterns of the same size are all family members. Home where kindergarten teachers display patterns. Whose home is this? What is the design area of this home? Ask three people to verify.
The kindergarten teacher has shown the chart.
Please compare the sizes of these three patterns, which is the largest and which is the smallest. Let's start with 1. (Talking about the teacher taking notes).
According to the size of the area, how do they line up? (The kindergarten teacher points to the record sheet) After finishing, the teacher asks, "What order do you arrange it? Are there any other arrangements? " ? Have you learned both methods? After arrangement, record the area of each pattern in several squares.
(2) My record sheet has been completed. I also prepared a record sheet for each group. Please ask four people in the 1 group. Everyone will take a pattern and a small square tool. When the pattern is measured and filled in, four people will arrange the area. (Kindergarten teachers have tools for children), and record the area of each pattern, and then ask the group leader to talk about it.
Verification: How many squares are there in the largest pattern area and how many squares are there in the smallest pattern? What order do you arrange them?
End: We measure and calculate squares to compare the areas of patterns. Let's go to the classroom to see what we have and try to compare the areas in this way.
Teaching plan 2 of "comparison area", the goal of big class mathematics activities;
1, understand several comparison methods of area.
2. Learn to draw squares and count squares to measure the area and compare the size of the area.
3. Knowing that the shapes of graphics with the same area are not necessarily the same, the initial impression is conservative.
Activity preparation:
All kinds of graphics, small squares
Activity flow:
First of all, combing the existing experience, comparing the size of the area in various ways, and introducing the concept of "area".
1, specific area by visual inspection.
The teacher showed two figures (green and blue) with very different sizes.
Teacher: "Which is the bigger of the two numbers?" (Child: "...") Teacher: "Oh, my eyes can tell at once."
2. The overlapping method compares the size of the area (the teacher shows two pieces of paper with little difference in size)
Teacher: Which is bigger now? Do you have any different opinions? (Child: "The orange one is big, the white one is big ...), Teacher:" They all look the same, how can they compare with the size? " (children: "overlapping")
Ask the children to come up and have a try.
Teacher: I think he is aligned with the corner on one side. What method did you use? This is called overlapping method.
Teacher: Which is bigger? When you are a little older, you will know it at once by overlapping method.
Conclusion: When two figures look similar, overlapping method is really a good way.
Teacher: Yes, when two things can't see who is bigger, overlapping method is really a good way.
3. Introduce the concept of "area"
Teacher: By comparing the two groups just now, we know that the surface of the figure is large and small, and the size of the figure has another name, which is called the area of the figure.
By comparison, it can be said that the area of green paper is larger than that of blue paper. The teacher pointed to another group and asked, What can this group say? . The area of yellow paper is larger than that of white paper.
4. Specific area of counting grid method
The teacher showed two irregular figures with the same area.
Teacher: There are two figures here, but the shapes are very strange. Which area is large? Is there (any) way to compare? Can we use the overlapping method?
Teacher: "Don't worry, I brought tools today. What is this? It can help two graphs to measure area and compare size.
How to measure? (The teacher sticks the figure on the blackboard) Align the corner of the square with the corner of the figure 1. Draw an outline, then overlap the edge with the corner of the outline just now, draw an outline, draw a line one by one from left to right, draw the next line, measure the picture, and measure the whole figure. Then use this small square in the same way, measure the number 2 and fill it up.
Teacher: I measured it. Do you know who is older and who is younger? (Child: Same age) How do you know? Six squares are used to measure the area of figure 1 and six squares are used to measure the area of figure 2. So their area is the same.
Teacher: Then let's count how many squares are used in the number 1 (the teacher keeps track while counting) and how many squares are used in the number 2. So their area is the same.
(Teacher's summary: It seems that although the graphics are different, the area will be the same. )
What method was used when it was larger than the area just now? (children: orthography), yes, we draw squares and count each grid, so it can be called counting grid method.
Teacher's summary: When two different shapes of graphics can't be compared in size, counting grids is really a good method. )
Second, the children's operation:
Teacher: The counting grid method is good. Would you like to have a try?
(A set of 4 numbers, 4 squares, Gou Xianbi)
I have prepared a figure and a small square for each of you in the basket behind the desk. Know the area of the figure by grid drawing and record it. Please don't bring a chair. Four people share a table. (After recording, put the small squares back in their original places, and put the graphics back in their original places to see who will sit down first.
2. Find your good friends and compare their areas; Compared with the other side, whose area is small.
Let the child come up: "Who did you compare with just now? Come on up, which one of you has a large area and who has a small area. Why is it not as big as your good friend's picture and text area? Why? Are they the same shape? It seems that figures with the same area can have different shapes. Who is in their district? Hold up your graphics.
(2) now, these graphics go home, the same size graphics they are all a family. The teacher shows the home of the picture. Whose home is this? What is the graphic area of this home? Ask three people to verify.
B, the teacher said that the map is ready.
Please compare these three figures. What size is the largest and what size is the smallest? Let's count from the first one. (Talking about the teacher taking notes).
According to the size of the area, how do they line up? (The teacher points to the record sheet) After finishing it, the teacher said, "What order did you arrange it? Are there any other arrangements? " ? Have you learned these two methods? After arrangement, each graphic area is recorded in several squares.
(2) My record sheet is ready, and I have also prepared a record sheet for each group of you. Please make a group of four people, each with a map and a small cube tool. After measuring and filling out the map, the four people will arrange the areas in order. (The teacher has children's tools), and record the area of each figure, then ask the group leader to talk about it.
Verification: How many squares are there in the largest graphic area and how many squares are there in the smallest graphic? What order do you arrange them?
End: We use a square to measure and count squares to compare the area of a graph. Let's go to the classroom and see what we can do to compare the area in this way.
Teaching objectives of lesson plan 3 in the comparison area of large class mathematics;
1, learn to measure the area and compare the size of the area by graphic method.
2. Cultivate children to take the initiative to explore and try, and give play to their creative thinking.
3. Cultivate children's patience and meticulous quality.
4. Stimulate children's interest in learning graphics.
5. Develop children's logical thinking ability.
Teaching preparation:
1, two copies of homework sheets with coordinate points and gardens painted on them; Pencils and erasers are one for each person.
2. Several square figures; Several small animals
Teaching process:
Introduce the topic first. Look, children, who is this? (Show Piggy) Piggy built a big garden on this land. (Showing the garden) The teacher is going to be a designer again, helping Piggy to make this garden beautiful.
Second, learning activities children, the garden is paved, is it beautiful? So how big is this garden? I don't know Then the teacher asked you, how many squares are there in this garden?
1, child counting grid (default)
2. The teacher and the children count together (the teacher writes it down one by one)
3. Summary: What method is not easy to make mistakes? Summary: This garden is as big as 18 square.
How did we know the size of the garden just now (counting squares), but it's too much trouble to put it on and take it off one by one? Is there any other simpler and more convenient way?
The teacher brought you a garden of chickens, rabbits, monkeys and sheep. Let's try to figure out how big their garden is.
1, kid, try it. By trying, in your own way, what is the area of the garden? And record the result in ().
2. Discussion and communication
How big is your garden? Do you know any good methods?
What methods should we use to avoid making mistakes?
Whose method do you think is the best? (mark and number) 3. Try again: use the method of marking or numbering the edges to get the exact size of the garden.
4. Summary: It turns out that although their gardens are different in shape, they are all the same in size.
Comparing the size of rabbits and cocks, we can see that the small animals have designed gardens of the same size, transformed their own gardens and paved them with beautiful colors. Do you want to see it? (The teacher shows two gardens with the same number of triangles and different numbers of squares) But they quarreled. The rabbit said, "My garden is very big." The little cock said, "My garden is very big!" " "Children, let's help them. Which of them has the bigger garden?
1. What's the difference between these two gardens? (more triangles)
2. What methods should we use? (Count the number of squares and triangles respectively and fill in the corresponding ().
3. Children guess whose area is big.
4. Teachers verify the results. The teacher took down the squares and triangles and compared them in two rows. The conclusion is that the rooster's garden is bigger than the rabbit's.
5. Mark the cock's garden and the rabbit's garden.
5. Children practice (instructing children to calculate the garden area with different numbers of squares and triangles) The cockerel was not convinced after learning the news. It quietly added two triangles to his garden. It thinks: The rabbit has only one square more than me, and now I have two triangles more than you. This time my garden is definitely bigger than the rabbit's! Children, is the rooster's garden really bigger than the rabbit's? Please think about it quickly.
1, guess the size after the child sits back.
2. Teachers guide children to draw a conclusion (guiding children to draw the conclusion that the size of two triangles is equal to the size of a square)
Add a five-pointed star to the rabbit.
The expansion of intransitive verb activity
Children, do you know who is bigger, two squares or four triangles? Will you tell your own teacher tomorrow?