Opening remarks] Thank you, judges, the topic of my trial lecture is "9 plus a few", (the title of the board book) will start the trial lecture below.
Teacher: Hello students, please take a seat.
1. Classroom introduction.
Teacher: Students, please look at the big screen, we came to a corner of the sports venue, what did you see?
Student 1: There are athletes and referees in the sports field.
Student 2: There is running, and there is shuttlecock kicking.
Teacher: Very good at observing, the athletes are very hard, the students of the service team bought boxed drinks for the athletes, how many boxes are in the carton?How many boxes are scattered?
Raw: There are 9 boxes in the carton and 4 boxes in loose boxes.
Teacher: Do you know how many boxes of drinks there are?How to column?Raw: 9+4=. (Board Book).
Pot Master: Observe this equation, we haven't learned it before, don't worry, in today's class, let's learn together Xi 9 plus a few. (Title of the board book).
2. Teaching of new courses.
a) The calculation method of **9+4.
Teacher: Please open the school tool bag, swing it with the help of a small stick, and think about it in a group of four people, how to calculate how many boxes there are?Timed for ten minutes.
Teacher: Which representative will tell us about your group's thoughts?
Group Representative 1: Our group is counted in order.
Teacher: This is your group's method, awesome, are there other groups that have different opinions?
Group Representative 2: Our group starts counting from 9 and counts all the way up to 13.
Teacher: Your group's method seems to be simpler than the first group, and you have solved the problem by using the number method, and I praise you for your wit!
Group representative 3: Our group first takes 1 small stick and 9 small sticks to make 10 sticks, and plus the remaining 3 sticks is 13 small sticks.
Teacher: Your group is really good at thinking and has come up with such a good solution. (2) Optimize the best algorithm and introduce the mind map.
Teacher: Through everyone's efforts, we have come up with so many good methods, and we have come up with 9+4=13. So, which method do you think is best?Why?
Student 1: I like the third group's method the most, you don't have to count, and you can know the result very quickly. Student 2: I also like the third group method the most because it's so simple.
Teacher: Yes, several methods are very good, but the teacher thinks that it is a bit troublesome to count one by one, and it is difficult to calculate how many 9 and 4 are combined, but if we can turn the drink into ten boxes, it will be easier to think about how many more than ten. Please look at the big screen, let's take 1 of the 4 boxes into the carton to make 10 boxes, 10 boxes plus the remaining 3 boxes are 13 boxes.
Teacher: We can also use this method to represent it with a mind map, please look at the blackboard. Let's decompose 4 into 1 and 3, 1 and 9 together are 10, and then 10 + 3 = 13. (Board Book Mind Map).
3) Use the method of making up ten to solve new problems 9+6
Teacher: Then the students went to the sports field and looked at it, now can you ask the problem of using addition to calculate?
Sheng: There are 9 athletes in the shuttlecock kicking group and 6 athletes in the running group
Same table type: 9+6 (board book).
Teacher: Now, please use the simple method we just learned Xi to complete it independently and time it for 2 minutes.
Teacher: Which student can tell me what you think?
Sheng: Divide 6 into 1 and 5, 1 and 9 together is 10, 10 plus 5 is 15, so 9 + 6 = 15. (Board Book Mind Map).
Teacher: The answer is really complete, and we will give him a round of applause.
4) Inductive algorithms.
Teacher: Students, looking at these two equations, how do we calculate how many times we add 9?Sheng: It's all changed from 9 plus a few to 10 plus a few.
Teacher: You've got to the point all of a sudden. So, how did we become 10 plus few?
Sheng: Split one of the numbers into 1 and several, and 1 and 9 make up 10, and it becomes 10 plus a few.
Teacher: That's right, in our mathematics, we call this method the Ten Methods. Let's remember this sentence: look at the big number, divide the decimal number, make up 10, and calculate the number.
3. Consolidate Xi.
Teacher: Next, please look at the two questions that you will do one by one, compete with each other at the same table, and compete with each other to see who can do it correctly and quickly.
Raw: 9+5=14. Raw: 9+7=16.
Teacher: Students, have you done the right thing?
Fourth, summarize the homework.
Teacher: Looking back on this lesson, what have you learned?Sheng: I can calculate the calculation of 9 plus a few.
Sheng: I know what is called the method of making up ten, and it is very convenient to use the method of making up ten to calculate 9 plus a few. Teacher: You have gained a lot. A pleasant class is coming to an end, please complete the remaining Xi after class, and students who have spare time to complete practical homework: write a math diary and communicate in the next class.
Teacher: After class, goodbye, students.
Conclusion] Thank you, teachers, and this is the end of my trial lecture.