Beijing normal university printing plate primary school mathematics classification

Knowledge Arrangement Course: _ _ _ _ _ _ Name: _ _ _ _ _ _ _

(A) the classification of numbers

Question: What numbers did we learn in primary school?

Positive integer (1, 2, 3, 4 ...) natural number

Integer 0

Negative integer (-1, -2, -3 ...)

Fraction (decimal)

(2) the meaning of numbers.

Question: Do you know the meaning of these numbers? (See the picture of P4 1 in this book-have a look.)

1, natural number: like 0, 1, 2, 3, 4, 5, ... is called _ _ _ _ _ _ _ _ _.

(1) _ _ _ _ _ _ is the basic unit of natural numbers. Any natural number consists of several 1 _ _ _ _ _ _ is the smallest natural number, and there is no largest natural number.

② Natural numbers have two meanings: first, they are used to represent the number of things, which is called _ _ _ _ _ _ _, such as "6" in six apples; The second is used to indicate the order of things, which is called _ _ _ _ _ _ _, such as "3" in the third row.

2. Negative integers: numbers like-1, -2, -3, -68 ... are called _ _ _ _ _ _ _.

(1) We have learned before that 4, 12, 9. 1, ... such a number greater than 0 is called _ _ _ _ _ _ _ _, and can be preceded by "+"; And numbers less than 0, such as -7,-16, -2.6 ... are all called _ _ _ _ _ _ _, and the preceding "-"is called _ _ _ _ _. _ _ _ _ _ _ _ _ neither affirms nor denies.

3. The role of zero: ① occupying a position in the number means that there is no previous unit in this position. ② indicates the starting point. (3) as a boundary. For example, it is the boundary between positive and negative numbers on the number axis. (See P42 in this book, question 4)

Practical application

1. Represents the following numbers in descending order on the number axis.

3.5、0、、、、-2 ( )

2. In 20, 0.3, 0, -3, 1.05, natural numbers have (), integers have (), negative numbers have (), fractions have (), and decimals have ().

3. () is the smallest natural number, that is, () is neither positive nor negative.

Practical application

1, five million six hundred thousand eight hundred and ninety writing (), rounded to ten thousand places is about () ten thousand.

2,300,502 writing (), rounded to 10,000 places is about () million.

3, 5.605 million writing (), rewritten as () million units.

4, 600,490 is written as (), rewritten as () million units.

5,120,800 writing (), rounded to 10,000 places is about () ten thousand.

6. A number consists of 300,000,4900, 15%. This number is written as () and rounded to ten thousand places, which is about () ten thousand.

7. One is composed of eight tens, three tenths and eight thousandths. This number is written as () and pronounced as ().

8. A number consists of 8.6 million, 900 and 3 10. This number is written as (). Rewrite it into () million, and round it to 10,000 places, which is about () million.

9. The highest digit of a number is ten million digits, and this number is () digits; If the number on the highest bit is the smallest odd number, the number on the thousand bits is the smallest prime number, and the rest is 0, this number is written as (), and then the number written as ten thousand units is ().

10 and 5006000 are pronounced as ().

A, 5.6 million b, 5.6 million c, 5.6 million

1 1, the correct pronunciation of the following genera is ().

A, 3 1.42 is pronounced 3 1.42b, and 50000600 is pronounced 500600.

12 and 72009 10 are pronounced as ().

A, 7.29 million b, 7.29 million c, 7.299 million.

13 and 50300040 1 are pronounced as ().

A, 503.41 million b, 503.41 million c, 503.41 million

The number consisting of 14, 15 decimals and 15% is ............. ().

a、 150. 15 B、 150.0 15 C、 15. 15

15, and the number in the following items is ().

A, unit B, billion C, three numbers.