Big class math bear cake 1 teaching plan;
1. Try to divide the common figures such as circle, triangle, square and rectangle equally, and know that some parts are smaller than the whole, and the whole is larger than the part.
2. Explore ways to understand different divisions of graphics and develop the flexibility of thinking.
Emphasis and difficulty of activity: explore different methods of dividing graphics.
Activity preparation:
1, knowledge preparation: children are familiar with the story of "two stupid bears" and common geometric figures.
2. Material preparation: circular, triangular, square, rectangular, pentagonal, trapezoidal, parallelogram pictures (each group of pictures is different), scissors.
Activity flow:
I. Review of experience
1, recalling stories
Lead: Do you remember the story of two stupid bears? What is the main point of this story? (Children casually answer)
Question: (showing a round cake) It turns out that two stupid bears can't share the cake, so they will be taken in by the fox. If it were you, how could you divide the cake into two pieces of the same size? Please come up and have a try (children discount)
Summary: Everyone has their own way, but sometimes they can't completely overlap after folding. Is there any good way to make it clear?
2. Experience improvement
Q: How can you prove that these two pieces are the same size? (The eyes can see that the two pieces are stacked together, overlapping)
Transition: Then let's see if it's the same size as two pieces (teacher overlapping verification)
Question: What's the difference between two separate cakes and the original one?
Summary: The method that we divide the shape into two pieces with the same size is called dichotomy.
Second, children's operation
1, Guide: Mother Bear bought some cakes today. She wants to divide these cakes into two cakes of the same size. She wants our children to do something for us. Let's see what shapes of cakes there are. (Square, rectangle, circle, triangle, trapezoid, parallelogram and pentagram are displayed)
Transition: Now, please choose a piece of cake you like and give it to Bear.
Requirements: 1) Divide into two cakes of the same size. 2) Explore different points.
2. Collective communication
Question: What shapes of cakes did you share? How did you split it in half? How to prove that two pieces are the same size? Are the two equal parts bigger or smaller than the original? Think about whether there are any other points. (The teacher can take the cake divided by the child for overlapping verification. )
Summary: The original method of bisecting a triangle is to become two small triangles. The way to divide a square equally is to turn it into two rectangles or two small triangles. The way to split a rectangle in two is to turn it into two long rectangles, two small rectangles or two small triangles. The way to divide the trapezoid equally is to become two small trapezoid. The separated cake is smaller than the original one.
Third, the extension of activities.
Transition: Today, we divide the cake into two parts of the same size. What if the mother bear has three babies and only one cake? The teacher put the information in the corner of the area, and we can also help the mother bear score a point when we study by ourselves.
Teaching objectives of big class math bear sharing cake lesson plan 2
1, learn to divide different shapes of food or graphics equally in calculation and judgment activities.
2. Know that the whole is greater than the part and the part is less than the whole, and cultivate the ability of comparative judgment.
3, preliminary training observation, comparison and reaction ability.
4. Let children learn simple math problems.
Key points and difficulties:
Observe and understand the characteristics of dichotomy
Try various dichotomies.
Teaching preparation
(Cognitive preparation) Understand symmetry knowledge.
(Material preparation) Round biscuits, rectangular biscuits, and various graphics. One Tu Tu Circle per person.
teaching process
First, the story: "Bears share bread" (the key point to be solved)
1, the teacher tells a story and understands what a fair share of bread is.
2. Question: How does the bear in the story divide the cookies? What is fairness?
Summary: Bear wants to share cookies fairly, that is, divide a cookie into two parts with the same size, and this one is divided into two parts.
Second, observe, judge and operate in two halves (solving problems)
1, please choose the graphic cookies on the table and divide them into two parts.
3. Ask children to come up and introduce their own dichotomy (guide and tell all kinds of dichotomy).
Summary: Through operation, we found that some graphs have various bisection methods. The equally divided figures are exactly the same size and can completely overlap.
3. Compare the size of the divided part and the original part?
Summary: The things divided equally are less and less than the original things, and smaller and smaller. This shows that if the number of equal parts is more, the divided parts will be less and less.
Third, consolidate and improve, and observe various graphics.
1, observe all kinds of graphs, and look for bisection method (visual guidance)
2. Discuss the bisection method of various graphs?
Summary: Just now, we divided equally by visual inspection. Anyone who can divide equally can find the symmetrical midline. Many places in life need to be divided equally by visual inspection. Accurate visual inspection is also a skill.
Fourth, children operate to draw circles (teachers tour guidance)
Activity reflection
This activity is in line with the age characteristics of children in large classes. The story of helping bears divide cakes runs through, with clear links, from shallow to deep, step by step. In the first part, the story causes the children to help the bear divide the cake in half. The second link is the focus of this activity, which mainly adopts individual, group and collective learning methods, so that children can divide all kinds of graphics equally, and discover and communicate different methods of division. The third link is to find out the gift of bisection and consolidate children's understanding of bisection. Because the whole activity runs through the story and is equipped with multimedia demonstrations, children's interest is particularly high, and every child can actively participate in the activity. I think this activity is worthy of recognition in three aspects: 1. The content is close to life. 2. Flexible form. 3. The materials are novel. Let children learn happily, which embodies playing middle school and learning while playing. The shortcomings of this activity are as follows: I asked my children to identify the "real objects" on the gift list. As a result, children often only pay attention to one and ignore the other, some only look at the left and right and ignore the up and down, some only look at the up and down and ignore the left and right, some only look at the shape and ignore the size, and some do not pay attention to the subtle differences of patterns. Therefore, the error rate of children in this link is relatively high, indicating that children have not really understood the concept of bisection. The problems exposed by children contain educational value, which is an effective starting point to guide children to deepen their understanding of mathematical concepts. Indeed, only through repeated operations and the use of different situations can children gradually accumulate mathematical experience and truly understand mathematical concepts.
The design intention of the big class mathematics bear cake teaching plan 3;
The value of mathematics education lies in bringing mathematics back to life, guiding children to face contradictions in life situations by using mathematical thinking mode, finding clues to solve problems, and improving children's ability to solve problems by using mathematical experience. In our daily life, we find that children usually like to divide snacks, toys and school supplies by themselves, but they often ask teachers for help because of unfair distribution. In order to help children improve their ability in this field, I designed the activity of "sharing cakes between bears" according to the characteristics of children's learning mathematics, and helped children understand and understand the dichotomy through the game mode of "teaching" bears' learning skills.
Activity objectives:
1. Try to divide a circle, a square and a rectangle equally, and know that some parts are smaller than the whole, and the whole is larger than some parts.
2. Experience the happiness of helping animal friends in the process of sharing cakes with bears.
3. Cultivate children's comparative judgment.
4. Stimulate children's interest in learning.
5. Experience the life of mathematics and the fun of mathematics games.
Activity preparation:
1. knowledge preparation: children are familiar with the story of "two stupid bears" and common geometric figures.
2. Material preparation: a number of circular, square and rectangular pictures, a pair of scissors, a watercolor pen and operation exercise paper, a display stand and six PPT (presentations).
Activity flow:
First, the story is imported.
Teacher: All the children have heard the story of two stupid bears. Because Big Black and Little Black can't share the cake fairly, the cake was almost eaten by Aunt Fox, so they want to learn how to share the cake fairly. Look, big black and little black are coming. (Show PPTl. )
Teacher: Can you help Big Black and Little Black? Let's see what different shapes of "cakes" big black and small black have brought (show PPT2. )
Second, learn to divide points.
(1) Learn to divide the circle into "cakes".
1. Ask individual children to help the bear divide the round cake into two parts with the same size.
Teacher: Who wants to help Big Black and Little Black divide this round cake into two parts with the same size (the teacher doesn't give any hints about the operation of individual children. )
2. Collective verification of children's classification is correct. (Guide children to discover that they can be verified by overlapping method. )
Teacher: See how he divides it. Do you think his division is correct? Why do people have different opinions? How to divide it?
3. Teacher's summary.
Teacher: It turns out that a round cake can be divided into two equal parts when it is folded in half. Two parts with the same shape and size are divided equally. The equal share is smaller than the original share, and the original share is larger. (show PPT3. )
(2) Learn to divide square and rectangular "cakes".
1. Lead out the task.
Teacher: Big Black and Little Black have learned how to divide round cakes, but they still can't divide cakes of other shapes. Let's teach them again, shall we?
Teacher: Here are some square and rectangular "cakes". Please find a piece of cake and divide it. Try to divide them into the same size. Think about a few points and write them down with a pen and paper.
(Children's operation, the teacher is concerned about whether children can divide the "cake" into two parts with the same size, and whether they can divide the "cake" in different ways from others. )
2. Exchange discussions.
Teacher: What shapes do you divide the "cake" into? How do you know if the division is the same? Who divides the "cake" into xx shapes? What method did you use (first communicate the division of square "cake" [show PPT4], and then communicate the division of rectangular "cake" [show PPT5]). )
The teacher summed it up.
Teacher: To know whether the square cake and the rectangular cake are the same size after being divided into two parts, we can compare them by methods such as edge-to-edge, corner-to-corner, up-and-down symmetry and overlapping.
Third, find a gift that is divided into two parts.
1. Explain the task.
Teacher: Big Black and Little Black learned the dichotomy with everyone's help. The following is a list of gifts brought by Big Black and Little Black. Big black and little black will test you to see if you can find half the gifts. (show PPT6. )
The children found a two-part gift in the handbook.
3. Collective communication and verification.
Teacher: What kinds of bisecting gifts did you find? Why do you think these gifts are divided equally?
Teacher: Let's verify it together. (The teacher clicks on every gift on PPT6. If it is divided into two parts, the computer will automatically circle the gifts and make a nice sound; If it is not halved, it will not be circled and will explode. )
Four. Promotional activities
Teacher: Today, we taught the ability to divide big black and small black into two parts. Are you glad that your skills are really great? In fact, besides these figures, there are many other figures, such as triangle and trapezoid, which can also be divided into two parts, or even four or eight parts. I'll put the materials in the corner, and you can continue to use your brain to try.
Activity reflection:
This activity is in line with the age characteristics of children in large classes. The story of helping bears divide cakes runs through, with clear links, from shallow to deep, step by step. In the first part, the story causes the children to help the bear divide the cake in half. The second link is the focus of this activity, which mainly adopts individual, group and collective learning methods, so that children can divide all kinds of graphics equally, and discover and communicate different methods of division. The third link is to find out the gift of bisection and consolidate children's understanding of bisection. Because the whole activity runs through the story and is equipped with multimedia demonstrations, children's interest is particularly high, and every child can actively participate in the activity. I think this activity is worthy of recognition in the following three aspects:
1. The content is close to life.
2. Flexible form.
3. The materials are novel.
Let children learn happily, which embodies playing middle school and learning while playing. The shortcomings of this activity are as follows: I asked my children to identify the "real objects" on the gift list. As a result, children often only pay attention to one and ignore the other, some only look at the left and right and ignore the up and down, some only look at the up and down and ignore the left and right, some only look at the shape and ignore the size, and some do not pay attention to the subtle differences of patterns. Therefore, the error rate of children in this link is relatively high, indicating that children have not really understood the concept of bisection. The problems exposed by children contain educational value, which is an effective starting point to guide children to deepen their understanding of mathematical concepts. Indeed, only through repeated operations and the use of different situations can children gradually accumulate mathematical experience and truly understand mathematical concepts.