The area of two graphs (1)... 13

Finishing and reviewing (1) 28

Sixty ............. 3 1

Mathematics and transportation ... 54

Finishing and reviewing (2)...6 1

Addition and subtraction of four fractions ........................

5. The area of the figure (2)...74

Try to guess .......... 78.

Finishing and reviewing (3) 82

Six possibilities ..... 85

Mathematics and life ... 89

Always look back at ............ 96.

Multiplies and factors of the first unit

1 the world of class hours

[Teaching Content] The World of Numbers (Page 2-3)

[Teaching objectives]

1, combined with the specific situation, know natural numbers and integers, and know multiples and factors related to multiplication.

2. Explore the method of finding multiples of a number. We can find all multiples of a natural number within 10 from the natural number 100.

3. Understand what divisibility is.

[Teaching Emphasis and Difficulties]

1. Explore the method of finding the multiple of a number. We can find multiples of all natural numbers within 1- 100 from the natural numbers.

2. Establish the concept of divisibility.

[Teaching process]

First of all, the digital world

Understand the situation of "fruit shop", there are natural numbers, negative numbers and decimals in life. And know natural numbers and integers, so as to further systematize the understanding of logarithm.

First, let the students observe the situation map, talk about the numbers in the map and classify them.

Second, factors and multiples.

1, in the process of solving the problems raised in the book, the formula is derived.

5×4=20 (yuan)

The meanings of multiples and factors are further explained, that is, 20 is a multiple of 4, 20 is also a multiple of 5, 4 is a factor of 20 and 5 is also a factor of 20. So as to understand the meaning of multiples and factors.

Then show a division formula, such as: 18÷6=3, to inspire students to think about whether the multiple relationship between two numbers can be determined according to the integer division formula. Emphasis: Factors and multiples are interdependent.

Note: When studying multiples and factors, the range is a non-zero natural number.

2. Show that A ÷ B = C (A, B, C are integers, and B is not 0) so that students can tell each other accurately. After the teacher explained: A is divisible by B, and B is divisible by A. 。

Third, look for it

1, judge whether the number given in the question is a multiple of 7, and communicate with your classmates.

Experience can be judged by thinking about multiplication or division.

2. Find the multiple of 7: the first net.

Guide the students to realize that you can generally find a multiple of a number by trying to multiply, so that students can understand that the number of multiples of a number is infinite.

Fourth, practice:

Question 2: Ask the students to find multiples of 4 and 6 and mark them with different symbols. Then let the students communicate and talk about the method of finding multiples. Finally, talk about which numbers are multiples of 4 and which are multiples of 6.

Question 3: Let the students finish it independently and think about how not to miss it.

[Blackboard Design]

Multiplication sum factor

Numbers like 0, 1, 2, 3, 4, 5, … are natural numbers.

Numbers like -3, -2,-1, 0, 1, 2, … are all integers.

A ÷ b = c (A, b, c, all integers, and b is not 0).

A is divisible by B. B is divisible by A. A is a multiple of B and C. B and C are factors of A. ..

second kind

[Teaching Content] Multiplication Characteristics of 2 and 5 (Page 4-5)

[Teaching objectives]

1, explore the characteristics of multiples of 2 and 5, understand the characteristics of multiples of 2 and 5, and judge whether a number is a multiple of 2 or a multiple of 5. m

2. Knowing the meaning of odd and even numbers, we can judge whether a number is odd or even.

[Teaching Emphasis and Difficulties] Understand the characteristics of multiples of 2 and 5 and judge whether a number is 2 or 5.