The first part: teaching material analysis, the second grade math teaching plan, selected by PEP.
"Two-digit plus two-digit oral calculation" is the content of the first lesson of Unit 7 in the second volume of Grade Two of People's Education Press. This part of the content is based on students' learning "two digits plus one digit", "two digits plus integer ten" and "writing two digits plus hyphen". Mastering some verbal arithmetic is not only useful in practice, but also the basis for learning written arithmetic in the future. The textbook creates a lively scene for sophomores to take a boat to Bird Island, aiming at solving the question "Can Class X and Class X of Senior Two sit down?" "Can I sit in Class X and Class X?" In this paper, two-digit non-carry addition (23+3 1) and carry addition (32+39) are introduced, and then students are encouraged to use their favorite oral calculation methods to calculate.
Analysis of learning situation
Students have learned "two digits plus one within 100, oral calculation of whole ten digits, and written calculation of two digits plus two digits". They can learn the "two-digit plus two-digit oral calculation" of this lesson by transferring analogy according to their existing knowledge. Through two trial lectures, it is found that most students like to decompose two addends into integer ten digits and one digit, add them with integer ten digits, add them with one digit, and then add them with one digit. Only a few students adopt the method of "only decomposing one addend and keeping the other addend unchanged".
Mathematics curriculum standards advocate the diversity of algorithms, but also require respect for students' personality differences and allow different algorithms to be used for calculation. Therefore, I think that in teaching, we should focus on guiding students to experience the process of exploring the oral calculation method of two-digit plus two-digit, and at the same time, while experiencing the diversity of algorithms, we should choose appropriate methods to skillfully perform oral calculation.
Teaching objectives
Knowledge goal: through students' own exploration of calculation methods, practical problems in life can be solved, so that students can correctly calculate two-digit plus two-digit (the sum is within 100). The experience algorithm is diversified.
Ability goal: to cultivate students' spirit of independent thinking and active exploration and the consciousness of active cooperation with classmates.
Emotion, attitude and values: let students experience the process of solving problems, the close connection between mathematics and life, and the joy of success. Integrate moral education and aesthetic education into teaching to stimulate students' enthusiasm for learning.
Teaching emphases and difficulties
Emphasis: Mastery and skillful application of oral calculation methods.
Difficulty: 1 Make students master the method of oral addition of two digits and calculate correctly.
2. Cultivate students' diversified problem-solving methods and improve the flexibility of thinking.
teaching process
First, create a situation to stimulate interest and introduce new ideas.
Xx Primary School organized second-grade students to have a spring outing to the beautiful Bird Island this spring. Students, please observe the map carefully.
Teacher: Look, what means of transportation do they take to Bird Island?
Second, cognitive perception, questioning
Can we put those two classes on the same boat? Why don't we do something together?
Third, interactive exploration, cooperation and exchange.
How can you calculate so fast? Would you like to tell us your algorithm?
Fourth, cooperation and communication, meaning construction.
1. Let's compare it. What are the similarities between the two questions?
Students, what did we learn today?
Blackboard writing: two-digit plus two-digit oral calculation (multimedia blackboard writing)
2. Let's compare it again. What's the difference between these two ways?
3. summary.
The second part: the symmetrical graphics selected in the second volume of the second grade mathematics teaching plan of People's Education Press.
Xx Road Primary School, xx City, xx Province
Teaching content: page xx of the second volume of the textbook "Compulsory Education Curriculum Standard Experiment" published by People's Education Press.
learning target
1. Through observation and operation activities, let students understand the basic characteristics of axisymmetric graphics.
2. Let the students understand the meaning of the axis of symmetry and draw the axis of symmetry of the axisymmetric figure.
3. Cultivate students' ability of observation and imagination, and feel the beauty of symmetrical graphics.
Emphasis and difficulty in teaching
Emphasis: Preliminary understanding of symmetrical figures and axes of symmetry.
Difficulty: Draw the symmetry axis of a symmetrical figure.
Teaching aid preparation: courseware
Prepare school tools: envelopes, paper, timely color stickers, scissors, rectangles, squares, circles, scissors, nail boards, watercolor paints.
teaching process
(1) import
1. Teacher: Students, the world we live in is made up of many beautiful objects. A green leaf and a beautiful butterfly can bring us beautiful enjoyment. Now, Miss Li has some beautiful pictures here. Do you want to see them? (thinking)
(courseware shows pictures)
Teacher: Who can tell me what's in the picture? (Butterflies, maple leaves, happy characters, Peking Opera masks)
Teacher: Is he right? Please observe carefully. Although these four objects are not of the same type, they all have a common feature. Students, talk to two people in the same place. Can you find this common ground? (Peer discussion)
Communication: I found that the left and right sides of these objects are the same.
Teacher: Have you all found this feature? (Yes) So how do you verify that they are exactly the same size on both sides?
(Students say what they think)
Teacher: Please look at the big screen. (The teacher explains while demonstrating the courseware)
Teacher: This is the maple leaf that just appeared. Let me fold it in half in the middle. What about its left and right sides? By the way, the left and right sides are completely coincident. Does this mean that the left and right dimensions are the same? (Yes)
Teacher: Like this, a figure whose two sides completely overlap after an object is folded in half is called a symmetrical figure. In this lesson, we will learn symmetric graphics together.
(Title on the blackboard: Symmetric graphics)
2. Teacher: Students, do you want to make a discount to verify it? (Students fold pictures by themselves)
Communication: What figure (butterfly) did you fold? Do you find it is a symmetrical figure? Butterfly is a symmetrical figure.
Teacher: Who folded it differently from him? (Students demonstrate their folded happy characters and Peking Opera masks)
3. A figure can be symmetrical left and right, up and down, or obliquely. Note: As long as they can completely overlap and have the same size after being folded in half, we can call them symmetrical figures.
4. Teacher: Just now, another crease appeared. Do you know what this crease is called?
Let's call this crease the symmetry axis. We usually use dotted lines to indicate it. Now please take out the symmetrical figure just now and draw its symmetry axis on it.
Teacher: How can I draw straight? (Draw with a ruler)
(Show the symmetry axis drawn by students)
5. Judge and draw the symmetry axis of the symmetrical figure.
Table tennis bat √ letter A√ 1 ×
Comb × pentagram √ Moon √
(2) cutting symmetrical figures
Teacher: The students made a correct judgment. (Show symmetrical figures on the blackboard)
Teacher: Please look at the blackboard. These patterns were all cut by teacher Li after class. Let's observe. Are they symmetrical? (Yes) How can I cut out truly symmetrical figures? Do you have any good ideas? Two people discuss it. (Peer discussion)
Communication: The teacher instructs the students: First, fold the paper in half, draw a half pattern with the broken line as the center, then cut it out and open it to form a symmetrical pattern.
Teacher: Before class, Miss Li sent some colorful stickers to everyone in time, so that students could cut a relatively simple symmetrical figure by themselves. Here we go.
(Students cut, teachers guide)
Comments: Cut the students and put the homework on the blackboard?
(Students evaluate other people's works)
(3) Symmetry axis of number symmetric graph
Teacher: Please take out the envelope. What's in it?
(rectangle, square, circle)
1. Take out a rectangular piece of paper and try to fold it. How many axes of symmetry does it have? (Article 2)
2. Square (4 squares)
3. Circle (countless)
Teacher's summary: There seems to be one axis of symmetry, several axes of symmetry and countless axes of symmetry.
(D) looking for symmetrical graphics
Teacher: We have learned so many symmetrical figures in this class. Please observe which objects in our classroom are symmetrical.
(Students answer, teachers explain)
Teacher: The students found a lot. In fact, symmetrical graphics are particularly useful in life. Do you want to broaden your horizons?
(showing symmetry)
Teacher's explanation: the appearance of the clock is symmetrical, which not only ensures the beauty, but also ensures the unity and accuracy of the clock; The symmetry of aircraft appearance can keep it balanced when flying in the air; The working people in our country have long discovered the beauty of symmetry. Look! There is an inherent symmetry between folk couplets and antithesis in ancient poetry. For example, China folk crafts, Chinese knots, window grilles, etc. Their symmetry fully embodies the artistic beauty of symmetry; Symmetry is also a biological phenomenon in nature, and many animals and plants have their own forms of symmetry. For example, a person's face is symmetrical with the tip of his nose, and his eyes, ears and mouth all grow symmetrically. The symmetry of eyes makes people observe objects more accurately, the symmetry of ears makes the sound we hear have a strong three-dimensional effect, and the symmetry of hands and feet can keep the balance of human body. Most clothes are symmetrical, and the symmetrical design looks more beautiful and solemn. Symmetry principle is also widely used in architecture. For example, the Forbidden City in Beijing is called the Forbidden City. Its overall layout is symmetrical. The first three halls and the last three palaces are on the axis of symmetry, and the other palaces are symmetrically distributed. It is the largest and most complete building complex in China. This is Nanpu cable-stayed bridge in Shanghai. Symmetrical designers' bridges are getting stronger and stronger. Please enjoy the symmetrical buildings in other countries, such as the Eiffel Tower in Paris, the Taj Mahal in Thailand and the Arc de Triomphe. These buildings are all symmetrical and harmonious in design.
(5) Hands-on practice
Teacher: Before class, I sent some articles to each of your groups. Please choose what you like and try to make symmetrical figures.
(Student activities)
Show:
(1) The classmate who used the pigment said: I first folded the paper in half, then opened it, drew half the figure along the symmetry axis, and then folded it in half, so that the pigment was printed on the other half of the paper and drew a symmetrical figure.
(2) Students who cut with scissors talk about methods. (omitted)
(3) Students who use nail boards to talk about methods. (omitted)
(4) The students who drew with checked paper said: I draw the symmetry axis first, then draw one side of the figure, and then draw the other side to compare with one side. The left side occupies several squares, and the right side also occupies several squares.
Classroom evaluation
(6) class summary
Teacher: What have you gained from learning this lesson?
(Students talk about harvest)
Teacher: The students speak very well. Symmetrical figures are beautiful. I hope the students can use their wisdom to create more symmetrical graphics and make our life better.
The third part: the teaching content selection of the second volume of the second grade mathematics teaching plan of People's Education Press;
The textbook is on page xx, and the exercises corresponding to Example 3 and Exercise 2.
Teaching objectives:
1, let students establish the concept of "average score" in rich practical activities.
2, through the operation and communication, independently explore ways to solve problems, and experience the diversification of problem-solving strategies.
3. Feel the role of "average score" in life and cultivate students' problem-solving ability and consciousness.
Teaching focus:
1. Establish the concept of average score in practice.
2. Cultivate students' problem-solving ability and consciousness.
Teaching difficulties: cultivate students' ability and consciousness to solve problems.
Teaching preparation: learning tools, theme maps, etc.
Teaching process:
First, create situations and introduce dialogues.
1, children, do you like spring outing? Where do you like to go for a spring outing?
2. Show the scene of the jelly problem. (Do not show the solution to the problem)
Teacher: Look! Please look at this picture carefully. What information did you get? What's the problem with the child in the picture?
3. Students observe pictures and exchange information.
Design intention: Introduce students' favorite spring outing activities, guide students to speak freely, exchange their favorite spring outing places, create a good learning situation for students, and stimulate students' learning desire. Guide students to learn to collect information and cultivate students' good study habits.
Second, explore new knowledge and solve practical problems.
1, learn from Example X, and draw the theme diagram of Example X.
2. Discuss and solve the problem of "how many copies can be divided" in groups.
Teacher: Can you use the information you collected to help them solve their problems? What can you do?
After four students discuss in groups, exchange their solutions and results.
3, the whole class exchange feedback, timely evaluation.
4. Summary: This question is actually to find out how many 2' s are in 8. If there are 4 2' s in 8, it can be divided into 4 parts.
Design intention: fully reflect the leading role of teachers and the main role of students, students actively participate in the learning process, and solve problems in the process of independent exploration and cooperation. Specific perception "every 2 points, 8 points are divided into such 4 groups, and 4 points are required." Let students learn from their classmates' problem-solving methods in exchange, experience success, further understand the method of average score, feel the application of average score in life, and let students feel the mathematics in life and the role of mathematics in life.
Third, connect with life and apply what you have learned.
1, question 5 on page xx of the textbook.
Q: What is the bear doing in the picture?
What's Bear thinking?
You can help bear share it. Guide the students to help the bear divide the chopsticks and use sticks instead of chopsticks. Guide students to think: How much do small animals eat? How many chopsticks are there in a pair? Then tell me how to divide it. )
2. Exercise 2, question 6.
(1) Question 6. Show me the scene of dividing corn.
Teacher: Look at the picture carefully. What information and questions did you get?
(2) Students finish independently, and then communicate the process and results of grading.
Fourth, the issue of openness.
1, students operate independently.
(1) Set five identical cuboids with 15 squares, with () squares for each cuboid.
(2) Each cuboid uses 3 wooden blocks, and () cuboids can be placed.
Thinking: What are the similarities and differences between these two questions?
2. Students find examples of using average scores in their lives and share them in groups.
Design intent: provide a well-thought-out problem scenario, such as "What are the similarities and differences between these two problems?" Guide students to observe and compare, so as to emphasize that the essence of average score is "each in his place" and deepen the understanding of the method of "average score" Use open-ended questions to provide students with broad and free learning space, encourage students to think boldly and explore deeply, encourage students to tell different examples as much as possible, and train students to think divergently and think divergently.
Verb (abbreviation of verb) course summary
Teaching reflection:
Chapter four: The concept of number selection in the second volume of the second grade mathematics teaching plan is the basis for students to learn mathematics. Students have learned "understanding of numbers within 20" and "understanding of numbers within 100", and the scope of understanding numbers will be expanded to 10000 this semester. At this stage, students will know more about natural numbers. It is not only the basis of large number calculation, but also widely used in daily life. Students must learn it well.
First, the content of this unit textbook
This unit includes counting, reading, writing, the composition of numbers, the meaning of numbers, the order and size comparison of numbers, divisor, addition and subtraction of whole hundred and whole thousand. The textbook integrates the above contents into the following logical structure.
Two. Overall teaching goal
According to the content of the textbook, establish the overall goal of this unit:
1. Let students experience the process of number and experience the generation and function of number. Can identify, read and write numbers within 10 thousand, and know that these numbers are composed of thousands, hundreds, tens and ones. Symbols and words can be used to describe the size of numbers within 10 thousand. Can say the name of each number and identify the meaning of each number.
2. Let the students feel the meaning of large numbers, know the divisor and estimate it according to the actual situation. Can calculate the whole hundred, add and subtract the whole thousand.
Chapter 5: Selection of teaching objectives in the second volume of the second grade mathematics teaching plan of People's Education Press.
1. Fully understand the role of parentheses in mixed operation, and use parentheses to calculate the disjoint of two-level mixed operation.
2. Understand and master the operation sequence of two-stage operation (parenthesis) mixed operation, and use the operation sequence correctly to calculate.
3. Guide students to form a good habit of looking at the operation sequence first and then calculating, and standardize the format of offline calculation.
Teaching focus
Understand and master the operation law of parenthetical mixed operation.
Teaching difficulties
Use the algorithm to calculate the parting.
Teaching process:
First, review the knowledge of brackets.
Remember the operation sequence of 58-( 14+6)?
58-( 14+6)
=58-20
=38
When students do off-line calculation, remind them to pay attention and mark the calculation content of the first step with a horizontal line. Delete the part that does not participate in the calculation. What we are going to learn in this lesson is also related to parentheses. (Two-step mixed operation with brackets)
Second, explore new knowledge.
(a) Try the mixed operation with brackets independently
7×(7-5)(77-42)÷7
(two) according to the performance of students, collective explanation.
Summarize the operating rules.
What are the similarities between these two formulas?
1 has parentheses; Both are two-stage operations; There are multiplication and division and subtraction.
In what order are the formulas in brackets calculated?
If there are brackets in the formula, we must first calculate what is inside the brackets, and then calculate what is outside the brackets.
Note that there are no numbers and operation symbols in the first line below the formula, and write the result of the second step in the second line. The equal sign should be aligned.
Third, consolidate the practice.
1. Compare exercises and find out the function of brackets.
Courseware shows exercises.
7×5-2 7×(5-2)
=35-2 =7×3
=33 =2 1
(1): What are the similarities and differences between the left and right questions?
(2) What role do brackets play here?
Note: the formula on the left has no brackets, multiply first and then subtract; The formula on the right has brackets. Calculate the subtraction in brackets first, and then calculate the multiplication outside brackets.
If there are parentheses in the summary formula, the parentheses count first. Through comparison, it is found that the function of parentheses can change different calculation results, and parentheses can also change the order of operation.
2. Fill in the blanks first, and then synthesize the formula.
On the basis of mastering the operation sequence of mixed operation with brackets, design layered exercises. In practice, it not only highlights the role of brackets, but also cultivates students' ability to synthesize formulas. This not only consolidates the new knowledge, but also lays a solid foundation for the next class.