First, the teaching content: the new curriculum standard People's Education Edition, the first grade mathematics volume 62-63 pages, such as 1, 1-2 do one thing and practice ten questions.
Second, the teaching objectives:
Knowledge and ability objectives:
1, so that students can understand and master the calculation method of integer decimal addition and subtraction, and can orally add and subtract integer decimal within 100.
2. Let students understand the operation of addition and subtraction on the same number.
3. Make students learn to use what they have learned to solve practical problems.
4. Cultivate students' ability to observe, analyze and solve problems.
Process and method objectives:
1, let students experience the generalization process of integer decimal addition and subtraction operation methods and the diversity of operation methods.
2. Cultivate the consciousness of independence, cooperation and inquiry, and improve the ability to describe the thinking process in mathematical language.
Emotional attitude and value goal;
1, let students feel the close connection between mathematics and life, and further stimulate students' interest in learning and intimacy with mathematics knowledge.
2. By creating situations, give students a learning space for independent inquiry and cooperative communication, and let students develop good study habits of independent inquiry and cooperative communication.
3. Let students master the algorithm through hands-on operation, independent exploration and cooperative communication, so as to improve their learning enthusiasm and enhance their interest in learning mathematics.
Third, the analysis of learning situation:
Through one semester's study, students have mastered the reading, writing and composition of numbers within 100, the addition and subtraction of whole ten, and the mixed operation of addition and subtraction. Students' study habits and learning ability also have a certain foundation, and they can use what they have learned to study simple math problems. Some psychological characteristics of elementary school students are figurative thinking, short attention time and love to talk and move.
Fourth, content analysis:
1, status:
Integer decimal addition and subtraction operation is based on students' basic mastery of reading, writing and composition of numbers within 100, as well as integer decimal addition and subtraction operation. It is the basis of learning addition and subtraction within 100 and learning multi-digit addition, subtraction, multiplication and division.
2. teaching material analysis:
The learning quality of this part will directly affect the correctness and rapidity of the calculation in the future. Because the addition and subtraction of integer decimal is based on the addition and subtraction within 10, but the counting unit is different. It takes "ten" as the counting unit, which permeates the meaning of addition and subtraction of the same digit, and lays the foundation for further research on addition and subtraction of two digits.
3. Teaching emphases and difficulties:
According to the teaching objectives and the above analysis of teaching materials, I have determined the following teaching priorities:
Teaching emphasis: make students understand and master the calculation method of integer decimal addition and subtraction.
According to students' existing learning experience, as well as their cognitive ability and psychological characteristics, the cognitive characteristics of junior high school students are a process from concrete to abstract and from low to high. The addition and subtraction of integer decimal is an abstract cognitive process for students, so the following teaching difficulties are identified:
Teaching difficulty: let students understand the addition and subtraction of numbers on the same number.
Suggestions on teaching verbs (abbreviation of verb);
Teaching methods:
In order to achieve teaching objectives, effectively highlight key points and break through difficulties, I use courseware to create situations, guide students to explore independently, ask questions and solve problems by themselves, and then explore a variety of different algorithms. In the whole teaching process, I am just a guide and organizer.
1, "calculation" is often associated with "boring" and "mechanical repetition". In teaching, through the vivid scene of showing students flowers, the calculation of adding, subtracting and rounding ten is put into the exploration with things and plots, so that the calculation contains rich and vivid concrete contents. Students study easily and happily, and the teaching objectives are effectively achieved.
2. When exploring the calculation method of integer decimal addition and subtraction, students can explore independently and show different algorithms through discussion and hands-on communication, which embodies the concept of "encouraging students to think independently and advocating diversification of calculation methods" in the curriculum standard.
3. Practice in the form of games and competitions that students like, dilute the traces of "practice", consolidate and practice relevant knowledge and skills, and develop mathematical thinking ability.
(2) Learning methods:
The teaching object of this class is first-year students. They are young, active, playful and curious, so they are prone to fatigue and distraction in forty minutes of teaching. According to this feature, in order to seize their interest and stimulate their curiosity, I adopted a pleasant teaching method, and with the help of teaching materials to see flowers, let students learn happily in the immersive situation. According to the curriculum standards, hands-on practice, independent exploration and cooperative communication are important ways for students to learn mathematics. In the teaching process, students can take a look (look at pictures), think (think about problems and algorithms), count, talk, wave their hands (swing a stick) and other forms, so that students can actively move their eyes, ears, brain and mouth, guide students to learn new knowledge through their own learning experience, and actively carry out teaching activities in this class. By adopting the learning method of group discussion and cooperative communication, students can observe and discover the operation independently and express it orally, which fully arouses their enthusiasm for learning, makes them feel the success of autonomous learning, cultivates their study habits of being good at observing and thinking, and more importantly, achieves the goal of cultivating their comprehensive ability. Encourage and guide students to think about calculation methods, organize students to exchange calculation methods, so that students can understand arithmetic and master algorithms in independent exploration and cooperative communication. It fully embodies the principle of students as the main body and teachers as the leading factor. It embodies the function of "students are the masters of mathematics learning, and teachers are the organizers, guides and collaborators of mathematics learning".
(3) Instructional design:
1. Create situations and introduce new lessons.
Teacher: Students, what season is it?
Health: Spring.
Teacher: Spring is the season when flowers are in full bloom. It's a beautiful day today. The teacher wants to take everyone to the garden. Do you want to go? (I think), there will be some difficulties on the way. Teachers are brave students who want to use their brains with love. Dare you accept the teacher's challenge?
(1) Courseware presents review questions.
(2) The courseware introduces the integer decimal system.
The design intention is to create a vivid situation to take students to see flowers and stimulate their interest and desire in learning. Make students experience the joy of success and enhance their self-confidence in learning.
2. Explore new knowledge.
(1) Explore the calculation method of integer plus integer.
First, create scenarios and obtain information
(1) walked into the scene. Students, the teacher promised you to play together just now. Now let's get started. Video display: The garden is full of flowers, flowers and butterflies, and the scenery is charming. By enjoying the beautiful scenery, who can find mathematical information and ask mathematical questions?
(2) Health: Observe the scene and collect figures (safflower 10 pots, 20 pots of yellow flowers and 30 pots of purple flowers. )
(3) Find the problem and make it clear. How many pots of safflower and yellow flower are there? Let the students read together, and then dictate the questions by themselves. )
(4) try to solve the problem. Write on the blackboard according to the students' answers: 10+20
B, cooperation and communication, exploring algorithms. How to calculate 10+20=? )
(1) teamwork communication algorithm.
(2) communicate and show, and understand reasoning.
A. numbering method:10,20,30
B: Put one bundle of sticks first, then two bundles of sticks. One * * * is three bundles of sticks, so 10+20 = 30.
C. Composition of numbers: 10 and 20 make up 30.
D. Calculation method: Because 1+2 = 3, 10+20 = 30.
E, take ten as the unit: 10 contains 1 10, and 20 contains two 10, which adds up to three 10, which is 30.
C, multifaceted, optimization algorithm.
Students' demonstration on stage: focus on the calculation method with ten as the counting unit. 10+20, 1 10 and two tens together. One * * * is three tens, which is 30. Then write on the blackboard:
10 + 20 = 30
↓ ↓ ↑
1 12 13 10
Summary: Add whole tens and think of tens and tens.
(2) Explore the calculation method of subtracting integer decimal from integer decimal.
A, scene reproduction. Show me the purple flower picture and the dialogue between the worker's uncle: the flower bed should still be decorated with purple flowers. I moved 10 pots. How many purple flowers are there? Let the students know the problems to be solved.
B, student report. According to the students' report on the blackboard: 30- 10
C, pay attention to experience, to increase or decrease. AC 30- 10 algorithm based on integer decimal calculation experience.
Health 1: I used the method of swinging a stick. One bundle MINUS three bundles leaves two bundles, and two bundles are 20.
Health 2: I calculated it by looking at what I want to add, because 10+20=30, so 30- 10 = 20.
Health 3: 3-1= 2,30-10 = 20.
D. Students' presentation on stage: focusing on the calculation method with ten as the counting unit. 30— 10=20。 Then write on the blackboard:
30 — 10 = 20
↓ ↓ ↑
3 Decades 1 Decades12Decades
Summary: subtract the whole ten from the whole ten, and think of several tens and subtract several tens. The design aims to let students enjoy flowers in the garden. Through observation, they find and put forward various mathematical problems, and then organize students to think about calculation methods and communicate with each other. This arrangement allows students to understand the calculation method of integer decimal addition and subtraction in independent exploration, thinking and cooperative communication, leaving time and space for students to explore, think, talk and practice, broadening students' thinking and cultivating students' cooperative spirit. At the same time, the discussion at the same table and group communication reflect the "interaction" of the research on the "harmonious classroom" model, "generate" different calculation methods of integer decimal addition and subtraction, and embody the concept of "encouraging students to think independently and advocating algorithm diversification" in the curriculum standard.
Step 3 consolidate the exercise
Page 62 of the textbook, question 1, 2
The teacher said: so many questions didn't bother you. It seems that you have mastered the knowledge of today. I hope you will review well after class.
4. Check the summary.
Teachers guide students to sum up. What did we learn in this class? What are you thinking when you add and subtract whole ten? Guide the students to read the abstract written on the blackboard. (Add whole tens, think of tens, tens. Subtract the whole ten from the whole ten, and think of several tens and subtract several tens. )