Jiangsu Education Edition Grade One Mathematics Courseware
Teaching content:
Page 65438 +0-2.
Teaching purpose:
1, let students experience the process of asking and solving problems from the actual situation, understand the calculation method of subtracting nine from more than ten, and accurately calculate the subtraction formula of subtracting nine from more than ten.
2. Let students operate and practice, explore ways to solve problems in practice, and attach importance to algorithms.
Diversification, develop students' innovative consciousness and cultivate the spirit of seeking differences.
3. Use the learned knowledge to solve the corresponding practical problems in life and realize the mathematical knowledge in life.
Important role.
Teaching emphases and difficulties:
Through hands-on practice and cooperation, let students explore the calculation method of ten MINUS nine.
Teaching aid preparation:
Corresponding CAI courseware and oral calculation card
Teaching process:
Suggestions on modifying the teaching process
Introduce scenes that students are interested in, stimulate students' curiosity, arouse students' interest, ask questions in life examples, and let students feel the connection between knowledge and life.
Ask the students to replace peaches with small plates, and put 13 in one pile and 3 in another according to the situation.
Let students talk more and think more about how they operate, strengthen the impression of operation, and let the impression of operation support the calculation of ten MINUS nine.
Maybe some students have other different algorithms, but no matter what method students use, as long as they can accurately calculate 13-9, there is no need to force students to use the same calculation method. Advocate algorithm diversification.
Let the students try boldly, explore the algorithm actively and independently, give the students space to explore, fully display their personality, and complete it in the form of group cooperation, thus cultivating the cooperative learning spirit of mutual assistance. So as to cultivate their cooperative communication ability and promote students' further understanding of the algorithm.
First, create situations and ask questions.
Monkeys sell peaches (the little monkey has 13 peaches, and the little rabbit bought 9 peaches. )
Q: How many rabbits are left after buying nine?
How do you know there are four left?
Guide the students to say: The little monkey used to have 13 peaches, but after selling nine, there are still four left.
Q: Can you list the formula according to the situation that monkeys sell peaches?
Blackboard: 13-9
Second, explore independently and comprehend the algorithm.
1, Q: How can we accurately calculate 13-9=?
Please think it over. You can put it on the table with your study tools and think in groups of four.
2. Each group reports the results of the activity.
First, each group will send a representative to give a presentation, express their views and explain their ideas. Subsequently, other students in the same group are allowed to supplement the students who spoke in this group and guide them to express themselves in an orderly manner.
Some students will subtract 13 small disks one by one, and then subtract nine in a row, leaving four;
Some students subtract 9 from a pile of 10, and then combine the remaining 1 with a pile of 3, leaving 4;
Some students subtract three from a pile and then take six from 10, leaving four;
Some students think so: because 9 plus 4 equals 13, 13 minus 9 equals 4;
3. The teacher affirmed and praised the correct algorithm that the students came up with.
Q: Among so many algorithms, which one do you like best? Then tell me why you like this algorithm.
4. Use your favorite method to calculate:
12-9=
16-9=
Third, consolidate practice and deepen application.
1, the first 1 topic of Thinking and Doing;
After the students understand the meaning by looking at the pictures, please ask them to use their favorite algorithm to accurately calculate 15-9= 17-9=.
2. Contrast exercises;
Fill in the form in groups, and then talk about the connection between the upper and lower questions.
For example, what do you think when you see 9+2= 1 1? Let the students know the relationship between increase and decrease.
3. Oral arithmetic contest (complete the fifth question on page 2 of the book);
Let the students who know the answer stand up and answer at once.
4, finishing;
According to the law, the formula of the fifth question is arranged as follows:
1 1-9= 14-9= 17-9=
12-9= 15-9= 18-9=
13-9= 16-9= 19-9=
5. Guide students to observe and initially perceive the skills of reducing one dozen.
Students ask questions from examples to make them feel the connection between knowledge and life.