A preliminary understanding of mathematical negative numbers in the second volume of the sixth grade of People's Education Press.
Teaching content:
A preliminary understanding of negative numbers, for example 1, 2,
Teaching objectives:
1. Knowledge goal enables students to get a preliminary understanding of negative numbers in real situations, understand the role of negative numbers, and feel the necessity and convenience of using negative numbers.
2. Ability goal enables students to know how to read and write positive and negative numbers, and know that 0 is neither positive nor negative. Positive numbers are all greater than 0, and negative numbers are all less than 0.
3. Be interested in the goal, make students realize the close relationship between mathematics and life, stimulate students' interest in learning mathematics, and cultivate students' ability to apply mathematics.
Teaching focus:
A preliminary understanding of positive and negative numbers, as well as reading and writing methods.
Teaching difficulties:
Understand that 0 is neither positive nor negative.
Teaching aid preparation:
Multimedia courseware, thermometer, exercise paper, cards, etc.
Teaching process:
I. connecting the past with the future
1, show the theme map. Topic map on the second page of the textbook.
2. Guide the students to observe the pictures and say what is in the pictures. Teacher: Look at the picture above. What can you find? What does 0℃ mean? What do -2℃ and 2℃ mean respectively? ) Introduction and blackboard writing: a preliminary understanding of negative numbers
Second, learn to lead.
1, teaching example 1.
(1) Key data of teacher's blackboard writing: 0℃.
(2) The teacher explained the meaning of 0℃: 0℃ indicates the temperature at which fresh water begins to freeze.
Temperatures below 0℃ are called sub-zero temperatures and usually begin with a number? -? (minus sign): For example, -2℃ means-2℃, which is pronounced as-3℃.
The temperature above 0℃ is called the temperature above zero. Supplement? +? (plus sign), which can be omitted in general: for example, +2℃ means 2 degrees Celsius above zero, which can be read as +3 degrees Celsius, or it can be written as 2 degrees Celsius and read as +3 degrees Celsius.
(2) Let's look at the pictures in the textbook. Do you know the temperature in Beijing? What are the highest and lowest temperatures? Feel free to answer
(4) Knowing the temperature in Beijing, I want to ask my classmates to tell me the temperature in Harbin. How does it compare with the temperature in Shanghai? Tell everyone by gesture, okay?
2. Students discuss cooperation and exchange feedback.
(1) Please write down the temperature in other places on the map and read it.
(2) Teachers show students different representations.
(2) Summary: Through the study just now, we use? +? And then what? -? It can accurately represent the temperature above zero and the temperature below zero.
3. Teaching example 2.
(1) The teacher shows the detailed schematic diagram of the passbook. Teacher: Can students talk about it? Expenditure (-) or (+)? Do the numbers in this column mean anything? Organize students to discuss and communicate in groups, and then report by name.
(2) Guide students to summarize.
Numbers like 2000 and 500 represent the amount of deposits; Is there one in front? -? Numbers, such as -500,-122, represent the amount of money spent.
(3) Teacher: Do 500 and -500 in the above data mean the same thing?
500 and -500 have opposite meanings, one is deposit and the other is expenditure.
Can you quickly and accurately show that you are east 100m, 200m west, 20 steps forward and 25 steps backward? Tell me what you said.
The teacher wrote the students' representative scores on the blackboard one by one.
4. Induce positive and negative numbers.
(1) Can you classify these figures on the blackboard? Discuss and communicate in groups.
(2) Teachers show the classification results and explain them in time.
Numbers like +8, +4, +2000, +500,+100, +20 are called positive numbers, and the preceding+sign can also be omitted.
Numbers like -8, -4, -500 and -20 are called negative numbers.
(3) So which category should 0 belong to?
Organize students to discuss and express their opinions to each other.
(4) Induction: 0 is neither a positive number nor a negative number, it is the dividing point between positive and negative numbers.
(5) Where have you seen negative numbers?
Encourage students to give more examples in combination with practice. The low temperature of 0℃ is called sub-zero temperature, which is usually added before the number? -? (minus sign): For example, -7℃ means minus 2 degrees Celsius, which is pronounced minus 3 degrees Celsius. Numbers like 2000 and 500 represent the amount of deposits; Is there one in front? -? Numbers, such as -500,-122, represent the amount of money spent. Numbers like +6, +4, +9 000, +600, +200 and +20 are called positive numbers, and the preceding+sign can also be omitted.
Numbers like -9, -2, -600 and -40 are called negative numbers.
Third, the use of detection.
1, complete page 4 of the textbook? Do it. Question 1. Organize students to finish independently and answer by name.
2. Complete page 4 of the textbook? Do it. Question 2.
Organize students to fill in the form by hand and communicate and check in groups.
Fourth, class summary.
What have you gained from learning this lesson?
Finish page 6 of the textbook? Do it. Question 1.2.
Organize students to fill in the form by hand and communicate and check in groups.
Blackboard design:
Understanding of negative numbers
0 is neither positive nor negative.
After reading the preliminary understanding of negative numbers in the second volume of mathematics in the sixth grade, people who read the lesson plans also read:
Teaching design of 1. Preliminary understanding of negative numbers
2. Primary comprehension exercises and answers of negative numbers in the first volume of Grade 6.
3. Reflection on the negative teaching of sixth grade mathematics
4. Optimal teaching plan design of negative numbers in mathematics.
5. The sixth grade math textbook is negative.