The teaching goal of adding and subtracting teaching plans within the second volume of senior one mathematics 100 (1);
1, so that students can master the oral calculation process of adding a number to an integer and the corresponding subtraction.
2, can calculate the whole number of ten plus one and the corresponding subtraction.
Process and method:
Guide students to participate in learning activities and experience the calculation method of integer plus one digit and the exploration process of corresponding subtraction.
Emotions, attitudes and values;
Cultivate students' enthusiasm for participating in mathematics activities and good study habits. Learning methods: hands-on operation, group cooperation, exchange and discussion. Teaching preparation: courseware or wall charts, wooden sticks and teaching pictures.
Teaching process:
Design Intention of Teachers' Activities Linking Students' Activities
Situational creation
1, finish the composition exercise about numbers proposed by the teacher orally.
2, students hands-on swing stick review: 3 tens and 5 ones, together is () ...
The teacher introduced the dialogue and created the situation: The blue mouse is our good study partner. Today, he came to our classroom and gave us a stick. What do you think he did? The courseware shows a stick diagram similar to the textbook diagram (first show 30 sticks, then show 5 sticks). Now, you also treat your own stick like a blue mouse.
Guide the students to say how to put it. Design students' favorite activities, stimulate students' enthusiasm for learning and cultivate students' interest in learning.
Exploration and experience
1, observe carefully, tell the meaning of the picture, ask questions and answer. There are 30 sticks on the left and 5 on the right. How many sticks are there in a box? The formula is 30+5=35.
2. Students know addend, addend and sum according to the teacher's requirements and the examples at the same table.
3. Students operate, communicate and express according to the pictures, and then report the communication.
4. Understand the minuend, subtraction and difference with examples.
Teacher's question: According to your operation, what questions can you ask? How to solve problems continuously? Talk in the group first, and then report.
The teacher guides the students to report and asks how to work it out, and writes on the blackboard: 30+5=35.
The teacher explained addend, addend and sum. Ask the students to retell these contents and give examples.
Back to the scene map, the teacher asked questions while demonstrating. How much is left? How to calculate in the form of columns? what do you think? Give it to the students for discussion. Ask the students to tell their own reasoning.
Explain the minuend, subtraction and difference. The method is as above. Teachers let students learn by themselves and give them enough time and space to operate, discuss and report. Stimulate students' love for learning on the premise of believing in their ability.
Practice and application
Students complete the exercises as required.
Independent world: Students write down their own problems in books.
Complete the second question of 1, 2, 3 (which can be practiced in various forms). Let the students look at the picture and say the meaning in the question, and calculate in parallel.
Question 4: Counterpart practice: You can use the teacher and a student to demonstrate (add and subtract) first, and then practice at the same table.
Take flexible and diverse forms to practice, stimulate students' interest in learning, and make students always maintain vigorous energy to participate in learning activities.
Analysis on the teaching design textbook of "Addition and subtraction within 100 (I)" in the second volume of junior one mathematics;
This course is a general step for students to master basic problem solving, and it is taught on the basis of learning the calculation experience of adding and subtracting two digits within 100. Adding the same number is a complicated practical problem. This lesson allows students to understand the meaning of problems by familiarizing themselves with situational diagrams, and find more complicated problems than before, thus stimulating students' desire to explore, cultivating students' ability to solve problems by drawing, listing and adding in exchange and cooperation, helping students to better grasp the structure of problems, enriching the experience of solving problems by adding the same numbers, and building a bridge from addition to multiplication, so as to facilitate students to better understand the meaning of multiplication in the future. Mastering the method of addition with the same sign in this lesson can not only make students further understand the significance of addition in practical application, but also accumulate experience foundation for learning multiplication in the future.
Teaching objectives:
1. Experience a variety of problem-solving strategies in operation, and master the operation method of seeking the sum of addends.
2. Experience the process of hands-on, cooperation and communication, comparison and optimization, and gradually master the problem-solving strategy. Improve the ability to use mathematical knowledge to solve practical problems.
3. Feel the connection between mathematics and life, experience the pleasure of successful inquiry activities, and reflect the application value of mathematics in life.
Teaching preparation: multimedia courseware and learning tools.
Teaching emphasis: master the calculation method of the sum of seeking common ground addends.
Teaching difficulties: the diversity of methods and the cultivation of optimization consciousness.
Teaching process:
First, review the old knowledge.
1, calculation (courseware)
8+8= 16+8= 8+8+8=
Step 2 create an exciting environment
Show me the star of wisdom.
Look what this is. (Lucky Star, Wisdom Star) Teachers often use it to praise those students who are disciplined, fond of thinking, enthusiastic and loud. Are you confident to do it? Then tell the teacher by posture.
Second, introduce the situation and clarify the problem
(1) Observe, collect and sort out mathematical information
There are also three students making stars. Go to the production site. Show theme map
1. Please look at the pictures carefully and read the text. Do you think it's weird (three students stacked small stars together, and each student stacked six. )
2. Who are these three classmates?
3. What do you mean by a 60% discount per person? Can I be more specific? (Jia Jia Li Liu, Hao Hao. . . )
What math questions can be asked according to the data? How many little stars did they break? )
(B) try to use strategies to solve problems.
1. We have found the mathematical information and problems. Can you solve this problem by yourself now? What method are you going to solve this problem?
2, student activities, independent thinking, and strive to find a solution to the problem.
Let the students finish in their exercise books.
Requirements: 1. You can use lists, draw pictures, calculate and choose your own methods freely.
Every student should not only understand the method by himself, but also let other children understand it. Talk to your deskmate after you finish.
2. Analysis and research, forming strategies
Communicate problem-solving methods, and realize the diversity of problem-solving methods in reporting and communication. (Courseware is presented as a link)
The default is:
Method 1: List method. Ask the students and analyze the meaning of each column in the table.
number of people
1
2
three
figure
six
12
18
The teacher asked: How is 12 calculated? 18?
Guide the students to say "1 has 60% discount, 20% discount 12% discount, and 30% discount 18 discount".
Method 2: Draw an arrow to indicate addition.
what do you think?
Method 3: Organize the learning tools first, and then calculate them in the form of columns.
6+6+6= 18 (pieces)
Teacher: Why add? Can you explain the meaning of this formula?
Teacher: What do you mean by the first six? What about the second one? What about the third one? The topic "Three students are folding little stars", where did 3 go? Why is there no 3 in the formula? 3 is it useless? Three people got six, so we added three sixes. )
Teacher: What are the characteristics of this formula?
Analysis and induction: the addends are the same, and each addend is 6.
Teacher: Every addend in the formula is the same. That's what we learned today, by adding the same addend to solve the problem.
3. Review and reflect, and test the results
Teacher: Students have different ways to solve this problem. Please recall which method do you like? why
Summary: When solving the same problem, we can use different methods to solve the problem, which can be enumerated or solved. When solving this kind of problems, we usually choose the method of column calculation (it is easier to guide students to understand column calculation).
Teacher: This question lists the formula. With the result, it's over? How should I check? Ask individual students to report and communicate "emphasizing the indispensability of inspection and verification in reporting and communication"
Teacher: Don't underestimate the inspection, it is very useful! It can help us find mistakes and correct them. "Now that you have checked, can you answer this question orally? (blackboard writing)
Third, comparative application, improve thinking
Solve the problem of broken stars in Xiao Fang, Hao Hao and Jiajia. Let's look at the problems of the other two children. Students can obtain mathematical information through observation.
Fold three little stars every day, obviously folding six little stars. They are a * * *, how many little stars have they lost?
First, let the students examine the questions themselves and answer independently "and then let individual students report and communicate"
Then the teacher threw out the following question: in the two problems we just solved, 3 and 6 appeared, but why are the formulas different? And the result is different? Let the students think independently and communicate at the same table "and then communicate with the whole class. "
Fourth, variant exercises are consolidated and improved.
1. Finish page 77 of the textbook, and then do it.
Students analyze independently and answer in their favorite way.
The whole class reports and exchanges.
2. I want to be a little teacher (pointing, speaking and writing on the platform)
Teacher: Can you find out the problem solved by adding the same numbers in the picture below?
First, let the students carefully observe the pictures and find out the problems that can be solved by adding the same numbers. Then, ask individual students to go to the podium and point to the screen and say which parts of the picture have such problems. Finally, let them write the corresponding formula on the blackboard. "Then let the whole class be judges and complete the answers and analysis of the exercises by playing different roles."
The teacher concluded: There are still many math problems in life. I hope every child can learn to observe, record and think in life, and then our learning wisdom will be more and more and better!
Fifth, talk about the harvest and summarize the class.
Student exchange
Teacher: What have you learned through today's study?
(2) Review and summary
Teacher: When solving a problem, first look at the pictures and words, find the mathematical information and the required mathematical problems from the questions, and then think about how to solve them. There are different ways to solve a problem, which can be solved by adding or listing. Finally, don't forget to check.
Teaching reflection The textbook of this unit is based on students' basic mastery of reading, writing and composition of numbers within 100, as well as the addition and subtraction of integer ten and numbers. I have achieved the following points in my teaching:
1. Let students learn computing in vivid and concrete situations, and cultivate their interest in learning and computing consciousness. For example, with the help of the resources provided by the flower delivery site designed by the teaching material, let students ask the question of adding and subtracting the whole ten, organize students to discuss and explore the calculation method. Put the addition and subtraction of integer decimal into the exploration of situations and plots, so that the operation contains rich and vivid concrete content. For another example, with the help of "issuing new books" and "buying toys" designed by teaching materials, students can create a space to ask calculation questions and calculate according to the actual situation.
2. Guide students to think independently and cooperate and communicate. In teaching, I carefully design and create meaningful problem situations or mathematical activities in combination with teaching materials, and encourage each student to think independently in hands-on practice; Encourage students to express their views and communicate with their peers. In this way, students are given enough time and space to explore, think, start work and speak freely, so that the purpose of acquiring knowledge and developing ability can be realized. Only by guiding students to think independently and explore knowledge can students gradually understand mathematics in their learning activities, promote cooperation between students and their peers, broaden their thinking and cultivate the spirit of cooperation.
3. Organize exercises to further develop computing ability. In the oral calculation of this unit, students are required to calculate correctly, and most students do 5~6 questions per minute. To achieve this goal, students should not only master the algorithm through hands-on operation, active exploration and cooperative communication, but also organize exercises to cultivate their computing ability.