Several levels are divided into four levels, ten thousand levels and one hundred million levels, and each level contains four counting units. One, ten, hundreds of thousands are levels, ten thousand, one hundred thousand, one million, ten million are levels, and hundreds, billions, billions and billions are levels. In this way, the four digits are divided into one grade, which is convenient for students to read and write with multiple digits.

Expanding the level of data is a reading method for people to remember Arabic numerals. On the basis of the value system (numerical order), read and write numbers according to the principle of three or four levels. Usually, in the writing of Arabic numerals, commas or spaces are used as the marks of each number level, and the numbers are separated from right to left, for example, 3,000,003,003,000; 271500 0000 2.7 billion150,000.

Reference level _ Baidu Encyclopedia