Learning situation analysis and design ideas;
Students understand the meaning of addition and subtraction, which will solve simple practical problems such as sum, remainder and addend. This lesson is a reflection on the problems left over. In teaching, teachers should fully connect mathematics with students' lives, make mathematics close to life, and let students really feel that mathematics is not boring and mathematics is around us. Teachers should strive to provide students with familiar situations, increase opportunities for practice, make them further understand the meaning of addition, and improve their ability to solve practical problems.
Teaching content: Jiangsu education publishing house, volume 2, grade one, 49 ~ 50 pages.
Teaching objective: 1. Knowledge and skills: Students can understand the quantitative relationship of practical questions such as "How many original pictures are there" in specific situations by exploring the process of "How many original pictures are there" and can answer them correctly.
2. Mathematical thinking: Use students' existing experience of "solving the practical problem of finding addend by subtraction" to understand the truth of finding the minuend by addition, so as to understand the meaning of addition more comprehensively.
3. Emotion and attitude: cultivate the consciousness and ability of using mathematical knowledge to solve practical problems and communicate with mathematics, and cultivate the attitude of cooperation with others.
Teaching emphasis: let students experience the quantitative relationship of practical problems such as "how much is it" in specific situations.
Teaching difficulty: understanding the quantitative relationship of how many practical problems are solved by addition.
Class record:
First, introduction before class
Dialogue: Are you nervous that so many teachers are coming to our class today? Introduce yourself first. If you speak well, you will be rewarded.
Student 1: ... Teacher: What courage.
Health 2: ... Teacher: Your voice is really loud.
Student 3: ... Teacher: You let us know about you at once.
Health 4: ... Teacher: It seems that you are a child with a wide range of hobbies.
In the interaction, the teacher gave each of the four students a strawberry card. Q: How many strawberries did the teacher give? Health: four.
Teacher: How many strawberries are left? Count together.
Health: 1, 2, 3, 3.
Teacher: How many strawberries did the teacher eat?
Health: Seven.
Teacher: How do you know?
Health: 4+3=7. Take back the four that were distributed, and add up the remaining three to make seven.
Teacher: it's hard to take it back if you give it. Can you solve it if you don't come back
Health: Just use 4+3=7.
Teacher's summary: As you can see, the teacher divided the original strawberry into two parts, one was finished and the other was left. How many strawberries do you need? Just combine the four handed out with the remaining three.
After introducing ourselves, we also solved a math problem. It seems that mathematics is really closely related to us. Today, Mr. Ma and his classmates come to have a math class.
Second, inquiry learning.
Dialogue: Cong Cong, a little monkey, is as good as you. He thinks seriously in class, speaks actively and helps his mother pick peaches. Let's go and have a look!
Media presenter: The peaches in Taoyuan are big and red. The little monkey can't wait to climb the peach tree and help his mother pick peaches. The female monkey said while counting. Teacher: Say what?
Health 1: 23 peaches have been picked, and there are five left on the tree.
Teacher: You pay great attention to the mathematical information in the topic. Who else wants to talk?
Health 2, 3: …
Teacher: What does mother monkey mean? Can you explain it to us? Name analysis.
Health: Twenty-three peaches were picked from the peach tree, and there are five more on the tree!
Teacher: We can understand this explanation better.
1, ask questions.
Teacher: as soon as mom said it, the little monkey was thinking, how many peaches are there on the tree? Who can fully explain this information?
Health: There are 23 peaches picked from the peach tree, and there are 5 left on the tree. How many peaches are there on the tree?
Teacher's evaluation: so complete. Who can say that? Say its name.
When I was born, I said that the teacher put a picture on the blackboard: 23 peaches have been picked (23 peaches have been picked and pasted on the blackboard), and there are 5 left on the tree (pasted). How many peaches are there on the tree?
Step 2 solve the problem.
(1) Teacher: The little monkey asked us how many peaches were on the tree. (Blackboard: How many red pens are there? )
Teacher: Will this problem be solved? Think for yourself before talking to your deskmate.
Class communication: Teacher: How many peaches are there on the tree? what do you think?
Health: 23+5=28. There were originally 28 peaches.
Teacher: Why add?
Health: Combine the 23 that have been picked with the 5 remaining on the tree.
Teacher: What a considerate child. Do you know what he thinks?
The students raised their hands.
Teacher: This "combination" (the teacher uses gestures) is well used. Once you say it, everyone will understand. Who said that again?
Pointing to several students, the teacher said: really listen, the more you say, the more complete you are. And gradually ask for specifications: How many peaches are there on the tree? It is necessary to combine the picked 23 with the remaining 5 on the tree.
Talk to each other in the same place
Please talk to a pair of colleagues. The lecturer commented: Good cooperation.
(2) Summary of the teacher's combined picture: Through the discussion of the students, we know that the peaches on the original tree are divided into two parts, one part is 23 that have been picked, and the other part is that there are 5 left. To figure out how many peaches there are, you have to combine the two parts and add them up.
3. Column calculation (blackboard writing: 23+5=28 or 5+23=28).
Teacher: Can you work out this formula?
Answer: 23+5=28.
Teacher: What do 23, 5 and 28 mean?
Health: 23 is to pick 23 peaches, 5 is to leave 5 peaches on the tree, and 28 is to put them together. There are 28 peaches on the tree.
Teacher: What does 23+5=28 mean?
Let's talk about the process of continuous thinking.
4. Instruct to write the name of the company.
Teacher: We found 28 peaches, and we wrote down the company name (each).
5. Guide oral answers.
Let's help him solve the monkey problem. Tell him the result. Answer the question.
Teacher: The children in our class are great. They solved the practical problem of "figuring out how many" (blackboard writing project) by themselves.
Third, practical application.
There are many such examples in life, let's take a look!
1, the first 1 topic of Thinking and Doing.
Teacher: Xiaoming and Xiaoli are doing puzzles together! What useful mathematical information do you know from the pictures?
Health: 2 1 piece has been assembled.
Teacher: Are you finished? Was born nodded. There is no answer. There are three pieces left to spell.
Teacher: Some information is hidden and not directly told to us, so we need to observe it carefully.
Health: There are 3 pieces left to spell.
Teacher: Where did you know that?
Health: Tully.
Teacher: You are so good at reading pictures that no one can find them. Point to each other in the same place and tell the information of the topic completely.
Teacher: How many pieces do you need for the puzzle? what do you think?
The tour guide said: How many pieces do you need for a jigsaw puzzle? That is, to combine the pieces that have been put together with the rest. Talk to your deskmate.
Production formula: 2 1+3 = 24 (block) or 3+2 1 = 24 (block)
Teacher: What do 2 1, 3 and 24 mean here?
Health: 2 1 is the number of blocks spelled, 3 is the number of blocks that have not been spelled, and 24 is a * * * *.
Teacher: What is the unit? (Block)
Oral answer.
2. "Think and act" question 2.
Teacher: After finishing the puzzle, they started a small train again. What useful mathematical information did you find from the picture?
Student: Seven people have got on the bus. Teacher: Did you see it? Where is it? This information is very valuable. Have you figured it out? Courseware demonstration 7 people boarding process)
Teacher: Your ability to collect information is getting stronger and stronger!
Ask to say it again completely. Say their names first, and then talk to each other at the same table.
(1) Students make their own lists, call the roll, and teachers patrol.
(2) Teacher: How many people need to take the bus? what do you think?
Dialogue: Just now we solved two problems together, and both of them can find useful information in the pictures. It's amazing. Are you willing to challenge a difficult problem now?
3. "Think and act" question 3.
Students give full information, answer independently and perform by name. Student evaluation.
Emphasize the significance of the formula 12+4= 16.
4. "Think and act" question 4.
Students solve problems in books independently, call the roll, and teachers patrol.
Students evaluate and improve the performance of the board of directors.
At this time, I asked emphatically: Is it different from what he wrote?
Fourth, the class summarizes.
Show pictures of solving problems and recall how many practical problems we have solved. What have you gained?
Blackboard design: