The answer process is as follows:

(1) The number 20 is a two-digit natural number, in which 2 occupies ten digits and 0 occupies one digit.

(2) The decimal place 2 means that 20 has two tens, and the decimal place 0 means that 20 has zero ones.

(3) The number of digits refers to the position occupied by each digit in a number. The number of digits in the integer part starts from the right, and every four digits are one level, and each level includes four digits, ten digits, hundreds and thousands.

Extended data:

In an integer, from right to left, the names of numbers are one, ten, thousand and ten thousand. For example, 2689, 9 is the unit, 8 is one tenth, 6 is one hundred, and 2 is one thousand.

The same number represents different values because of different digits. For example, among the three numbers of 6789, 9768 and 6987, the "9" of 6789 is in one unit, that is, 9 1, the "9" of 9768 is in a thousand miles, that is, 9 thousand, and the "9" of 6987 is in a hundred miles, that is, 9 hundred. ?

A number represented by a nonzero number is called a single digit. For example, 2, 4, 6 and 8 are all single digits. Numbers represented by two numbers (ten of which are not zero) are called double digits, and 10, 24, 19, 89 and 92 are all double digits. A number consisting of more than two digits (the highest digit is not zero) is called a multi-digit. For example, 239 is three digits, 2467 is four digits, and 123456 is six digits.