1 .1 (1), ten, hundred, thousand, ten thousand ... are counting units; Units, ten, hundred, thousand and ten thousand are all numbers; Numbers and counting units are in one-to-one correspondence.

2. Starting from each digit in the numerical sequence table, the higher the digit, the left, and every four digits form a numerical level (level: one digit, ten digits, hundred digits, thousand digits; Ten thousand: ten thousand, one hundred thousand, one million, ten million; .....) emphasize that the unit is not the lowest place.

The series between every two adjacent numbers is ten. This counting method is called decimal counting method. When natural numbers (1, 2, 3, 4, 5, 6 ...) represent the number of objects, none of them are represented by 0, and 0 is also a natural number. Understand the one-to-one correspondence between natural numbers and object numbers. )

Second, reading and writing within 100 million.

1. Read the numbers below. (Level 4, draw the grading line first. )

(Step by step reading; Read first 10000 and then read again 10; Ten thousand levels are read according to each level, and the word "ten thousand" is added after reading; Do not read 0 at the end of the phase; One or several other zero read-only 1. )

24678090 1000000 1 2659000

2. Write down the following figures. Draw a score line after ten thousand words. )

(write by level; Write ten thousand levels first and then one level; There is no unit on any number, so write "0" to get the position. Key point: 10,000 levels are completely written before considering the next level. Read a zero, and you may write multiple zeros. )

10,400,50 1,007

Third, reading and writing exceeds 1 100 million. Similar to the reading and writing method within 100 million, it is the promotion and extension of reading and writing within 100 million. )

1. Read the numbers below.

1925080030 433040333005 10000000005

2. Write down the following figures.

209,404,400,400.

Fourth, the composition of numbers.

1. A number consists of four million, seven hundred thousand and five tens. This number is ().

Analysis: Millions of bits are 4, 100,000 bits are 7, ten bits are 5, and the rest are 0.

2. Write a number consisting of the following numbers.

(1), four million, eight hundred thousand, fifty thousand, three thousand.

② 80 million and 40 million.

The same idea.

3.30900500 consists of (), (), () and ().

Analysis: according to the meaning of the question, fill in the meaning represented by three non-zero numbers. Like three tens of millions.

4. Variant questions.

300000000+500000+4000+9=( )

Analysis: The results should be composed of 300 million, 5 1 00,000, 4,000 and 91.The method is the same as the above exercise.

Verbs (abbreviation of verb) are rewritten and omitted.

1. Rewrite. (4 zeros are replaced by a word "ten thousand", and the integer of ten thousand is rewritten as a number with "ten thousand" as the unit; A word "100 million" has 8 zeros, and the integer of 100 million is rewritten into a number with "100 million" as the unit. )

3000000= () million 80000000= () million

1200000000= () billion 5000000000 = () billion

2. Omit.

Find the approximate number by rounding, and see 0, 1, 2, 3, 4; See 5, 6, 7, 8, 9 (go forward, omit the mantissa. )

Omit the mantissa after ten thousand digits, and round the thousand digits.

12678≈ 10000 439807≈440000

Omit the number after the hundredth digit and round it to ten digits.

12678≈ 12700 439807≈439800

…………

Whether to leave or enter depends on the highest position of the omitted part.

3.346709 ≈ () billion 1054433 ≈ () billion

There are two steps: (1) approximation. (2) rewriting.

4. Approximate value and exact number.

The numerical values of the words "about", "near" and "many" are approximate values, and only numbers and units (such as 155 people and 46 million yuan) are accurate numbers.