2, can correctly calculate the carry addition of numbers within 20.
3, can use carry addition to solve simple practical problems in life and experience the fun of using mathematics.
The teaching focus can correctly calculate 7 plus several, 6 plus several, 5 plus several, 4 plus several and 3 plus several, and master the oral calculation method.
It is very difficult to cultivate the ability of migration in teaching, and it will draw inferences from others.
Teaching methods try to guide the law.
Prepare CAI courseware as a teaching aid and paste it
Revision of teaching activity design
First, create situations and introduce new lessons.
(1) Teacher: In a beautiful big forest, there is a very big tree with 9 birds on it. Look! Six more flew in. How many birds are there now? Who can figure it out?
Health:? Answer the formula and talk about the calculation method. )
(2) If there are 8 birds in the tree and 6 birds fly in, how many are there? Who will count this time? Students continue to think and answer according to the created story situation. )
(3) Please continue to accept the challenge: If there are seven birds in the tree, how about six more? How to ask questions? How to calculate?
(4) Summary: Today, we continue to learn the addition of 7, 6, 5, 4 and 3 with the calculation method we learned a few days ago. (blackboard writing topic)
Second, cooperate to explore and learn new knowledge.
1, * * * Follow 7+6.
(1) Let's put a stick between our desks. what do you think?
(2) report by name. (roll call to the front of the podium, explain while operating, and the teacher will dial)
(3) Teachers write on the blackboard according to the students' answers.
2. Do it and say it.
Be able to understand the arithmetic explained by various forms of arithmetic activities. )
3. Circle the union number.
Further understand the strategy and calculation process of "rounding"
4. Think about it and fill it in.
(Intention: (1) Consolidate students' computing ability; (2) Through calculation, observe and continue to fill in the formulas, and guide students to discover the laws between formulas).
Fourth, consolidate practice and deepen experience.
Instruct the students to complete an exercise.
The teacher lets the students try boldly, explore independently and open up their minds. )
For example: Question 1: How do you communicate collectively after students complete their independence? Which method is the simplest? Tell me how you did it. What ingenious methods do you have? What other patterns did you find? )
Fifth, class summary and optimization algorithm.
Today, we found that there are many ways to calculate the addition of 7, 6, 5, 4, 3 and 2. Can you talk about these methods? If you think it is simple, use that method to calculate.
How many birds are there in the blackboard design (7, 6, 5, 4, 3 plus a few)
7 + 6 = 13 7 + 6 = 13