1, digit, refers to the position of each digit in a number. The number of digits in the integer part starts from the right, and every four digits are one level.

2. Counting is a mathematical behavior of repeatedly adding (or subtracting) 1, which is usually used to calculate how many objects there are or to place as many objects as you want (counting the first object from the beginning and corresponding the remaining objects to the natural numbers starting from two).

3. China's reading habit is to use four digits as the scoring method. Such as: ten thousand (four zeros after counting) and trillion (there are two kinds of sayings, one is one million, that is, six zeros after counting; The second is trillions, that is, 12 digits followed by zeros) and 1 billion (8 zeros followed by digits), which is the Sino-French count). These levels are called Level 1, Level 10,000 and Level 100 million respectively.

Extended data:

finger

For example, one, ten, one hundred, one thousand, ten thousand, one hundred thousand and so on. It is called the counting unit of numbers. These counting units are arranged in a certain order, and their positions are called numbers.

We usually use decimal notation. The so-called decimal refers to the relationship between every two adjacent counting units: one large unit equals ten small units, that is, the forward speed between them is "ten".

Counting units should include two parts: integer part and decimal part, which are arranged in the following order: ... one hundred billion, ten billion, one hundred million, one hundred thousand, one hundred thousand, one hundred, ten, one tenth, one percent, one thousandth, ... The integer part has no maximum counting unit, and the decimal part has no minimum counting unit. When writing numbers, if there is a decimal part, use the decimal point (. ) to separate integers from decimals.

Three-position classification

That is, the three-digit grading method. This western classification, this classification is also an internationally accepted classification. That is, take the decimal point as the center and add a comma to every three numbers in the integer part from right to left. Such as: thousands, three zeros after the number; Millions, six zeros after the number; One billion, nine zeros after the number.

References:

Baidu encyclopedia-several levels

Baidu encyclopedia-counting