P. 1, 2, complete the exercises on page 3 and the questions in 1/~ 5.

Teaching objectives

1, understand the background of negative numbers in real situations, understand the meaning of positive and negative numbers and zero, master the representation method of positive and negative numbers, and know that 0 is neither positive nor negative.

2. Master the reading and writing methods of positive numbers and negative numbers. And can read and write correctly.

3. Experiencing mathematics is closely related to daily life, and some successful experiences are gained to stimulate students' interest in mathematics.

Teaching focus

The difficulty in teaching is to understand the meaning of positive and negative numbers and zero in real situations.

Describe the phenomena in life with positive and negative numbers.

Exploration, discussion and exchange of teaching methods and means.

Teaching preparation related courseware.

teach

study

get through

travel

First, dialogue import:

Do you know what to learn in this class through review? (blackboard writing: negative number)

What numbers have we known before? (natural numbers, decimals, fractions)

Give examples respectively. It is pointed out that natural numbers are the most common, decimals have special marks "decimal point" and fractions have special marks "fractional line". Do you know any special signs of negative numbers? (minus sign, similar to subtraction)

Second, the learning example 1:

1, Dialogue: Do you know the temperature today? Can you find this temperature on the thermometer?

2. Description: Introduce the thermometer: (1)℃, ℉, which is our domestic unit, namely℃; ℉ is Fahrenheit, which is used in Europe and America. (2) With 0 as the boundary, the temperature above 0 means above zero, and the temperature below 0 means below zero. (3) scale. Pay attention to how many degrees the big grid and the small grid represent respectively.

3. Student identification: Find the scale indicating 35℃ on the thermometer.

Dialogue 4: Do you know when it is 0℃? (mixture of water and ice)

5. Dialogue: Do you know the lowest temperature in Jiangdu for one year? Can you find it on the thermometer?

6. Know the temperature of three cities in the textbook.

7. Discussion: Talk about your feelings about the temperatures in these three different cities.

8. Try to read and write.

9. Question: Is +20 the same as -20?

Third, study example 2:

1, Dialogue: Introduce the situation map in the textbook.

2. Panel discussion: What do you know?

3. The whole class reports and exchanges.

4. To sum up: the altitude is usually based on sea level, and how many meters above sea level is how many meters above sea level; How many meters below sea level is how many meters below sea level.

Fourth, induction:

1, Conversation: Through example 1 and example 2, everyone should know the usage of positive and negative numbers in life. Can you give me an example?

2. report and exchange.

Verb (abbreviation for verb) consolidation exercise

1. indicates the completion of the second "exercise" of the moth. (Focus 0)

2. Finish the first exercise. (Emphasize that negative numbers include integers, decimals and fractions)

3. Finish the second exercise. By the way, the situation of these two lakes.

3. Complete the third exercise.

4. Complete the fourth exercise.

6. class summary: ask questions. What did you learn from today's study? What do you want to say to everyone? Review after class