First, "grinding" textbooks and students.
The collective lesson preparation activities of our fifth grade preparation group are in the form of collective grinding. In the process of grinding classes, everyone not only has a deeper understanding of the teaching materials, but also develops the habit of timely reflection in the process of going back and forth. Standing on the level of science and art teaching, they ask their own classes to ponder and grow together in the grinding class. Last semester of grade five, everyone said that the lesson of "digital coding" in "wide angle of mathematics" was particularly difficult, so we decided to polish the content of the preparation group this semester as "wide angle of mathematics-numbers and coding" Example 2.
The first part of the collective lesson preparation activity is "preparing lessons independently". After all the members of the lesson preparation team have designed their own classroom presuppositions, in the second part of "Comparative Research Class", two teachers in the group first showed their classroom teaching designs to everyone. After class, everyone had a heated discussion on the teaching of this class. The focus of the discussion is: Why are the classes boring and the students not active? Thirdly, it is analyzed and discussed seriously from two aspects: teaching materials and students.
1. What are the teaching objectives and key points of Example 2?
The whole unit of "Mathematics Wide Angle-Digital Coding" has four examples (each example is regarded as a knowledge point), namely four knowledge points. Example 2 is the second knowledge point. The overall structure of these four knowledge points is divided into two parts: one part is case 1, and the other part is case 2, which takes postal code and ID number as carriers respectively, so that students can understand that besides cardinal number and ordinal number, numbers can also be used for coding. Feel the wide application of digital coding in life and explore simple methods of digital coding. The second is case 3 and case 4. Arrange two practical activities of coding with numbers or letters (numbers for students and numbering books in the library), so that students can further understand the coding law and the thinking method of coding in the activity of trying to code. According to different teaching emphases, the four examples form a closely linked whole, highlighting the simple method and social value of digital coding and the thinking method of digital coding.
Example 2 is based on example 1. Example 1 only requires students to understand the structure of postal code, the meaning of each paragraph of numbers, and initially perceive the coding idea. But the teaching of Example 2 should go further. Its arrangement is divided into two levels: (1) introduces the identification of ID number. The textbook presents scenes such as "security check, handling savings business" to let students know the importance of ID number; (2) Understand the composition of the ID number through group activities. With questions as the main line, guide students to understand the information and meaning contained in the ID number (birth date code, address code, gender code, sequence code and check code). The arrangement intention is: (1) Take the ID number as the carrier, so that students can further understand that the number can be used not only for cardinal number and ordinal number, but also for coding, and realize the irreplaceable significance of ID card in social life. (2) Through observing, guessing, comparing, judging and other activities, guide students to explore simple methods of digital coding, and realize the scientificity, standardization, uniqueness and conciseness of coding. A preliminary understanding of the thinking method of digital coding is the core content of teaching example 2.
After further study and analysis of the textbook, everyone agrees that the specific teaching objectives of Example 2 should be: (1) Let students collect their family members' or relatives' ID numbers before class; (2) By observing, comparing and guessing, we can understand various information contained in the ID number and explore a simple digital coding method; (3) Through the above activities, I realized the scientificity, standardization, uniqueness and conciseness of digital coding, and initially realized the thinking method of digital coding.
2. What do the students already know?
Through the pre-class investigation and the study of the example 1, we can understand the students' life codes (ID card, car license plate, student number, etc. ) Still superficial. Most students only know the meaning of numbers, but they don't understand the arrangement rules contained in numbers, and they can't understand the coding ideas.
Through collective analysis and research, we have a deep understanding of the arrangement intention of teaching materials and students' existing foundation, and the classroom teaching ideas are gradually clear in our minds. A week later is the last link of collective lesson preparation activities-wonderful interpretation. After synthesizing the opinions of the members of the preparation group, I revised everyone's teaching design. Starting from the psychological needs of students' learning, we should try our best to use the relevant resources among students to carry out teaching activities, and strive for the harmonious unity of theory and practicality, boredom and interest.
Second, a wonderful review
Teaching practice shows that students are very happy. After class, I sorted out some happy fragments between me and my students.
1. Preparation before class
One week before class, I arranged for students to collect their and their family's ID numbers and let them copy them carefully on the form. After introducing the topic, I asked them to observe their numbers in groups and guess what information is contained in the ID number and what is its arrangement law. Students compare their collected figures with great interest and carefully ponder the arrangement rules.
2. Know the birthday code by using the wrong resources skillfully
The next day in math class, I asked a student to say his ID number out loud.
He said, "330621109712178278."
I secretly pleased: thank you, little guy, the "riot" in the class is coming. Unsurprisingly, many clever children shouted, "Mr. Jiang, he, he made it up!" "
I pretended to be dissatisfied and said, "You can't talk nonsense without foundation."
"He's almost a thousand years old!"
"Are you? Where did you see it? "
"Through comparison, we found that the ID number * * * has 18 digits, and the 7th to 14 digits indicate his birthday. How could this person be born in February of 1097 17? "
Great, I watched my classmates happy and secretly happy: this is what I want.
The student looked very wronged, so I quickly said, "Yes, you are really amazing. You can find a big problem on the ID number. However, I don't think he made it up. It seems that he copied 9 into 0. Do you think so? " (Most students nodded in agreement) Then they said to the students who made mistakes, "Be careful next time, or you will make a joke."
After the students sat down, I took a deep breath and said, "In the past, only my parents remembered our birthdays, but we didn't remember our parents' birthdays. Today is a good opportunity to remember their birthdays. Please read your parents' birthdays out loud, remember these numbers carefully, and say happy birthday to them when their birthdays come. " The students remember it very carefully.
I wrote another ID number on the blackboard: "Guess whose ID number is this?"
Many students shook their heads, and some clever students screamed, "This is Mr. Jiang's."
"How do you know?"
"The number shows that this person was born in April 1975, 13. Teacher Jiang, you are probably in your thirties. And I found that the penultimate digit of many girls is a double number, and the penultimate digit of this number is also a double number. This indicates a person's gender. Teacher Jiang, you are a woman, so this number is yours. "