The decimal part of a number, with irregular arrangement and infinite digits, is called infinite acyclic decimal. ?
Second, infinite cyclic decimals
In the decimal part of a number, one number or several numbers appear repeatedly in turn, and this number is called cyclic decimal. For example: 3.555 … 0.0333 …12.15438+009 …
Third, finite decimals
The number of digits in the decimal part is a finite decimal, which is called a finite decimal. For example, 4 1.7, 25.3 and 0.23 are all finite decimals.
Fourth, infinite decimals
The number of digits in the decimal part is infinite decimal, which is called infinite decimal. For example: 4.33...3. 145438+05926 ...
Five, pure cycle decimal
The cyclic part starting from the first position of the decimal part is called pure cyclic decimal. For example: 3.111.5656 ...
Sixth, mixed cyclic decimals.
The loop part does not start with the first decimal part, which is called mixed loop decimal. 3. 1222 ...0.03333 ... When writing a cyclic decimal, you only need to write a cyclic segment for the cyclic part of the decimal, and point a point at the first and last bit of this cyclic segment. If there is only one number in the circle, just click a point on it.
Extended data
First, turn pure circular decimals into fractions.
Methods: The pure cyclic decimal was rewritten as a fraction, and the numerator was a number composed of numbers in the cyclic segment. Every bit of the denominator is 9, and the number of 9 is the same as that of the loop segment, and it can be subtracted again at last.
Second, mix the cyclic decimals into component numbers.
Methods: The mixed circulating decimal was rewritten as a fraction, and the numerator was the difference between the number of decimal parts in the circulating segment and the number of non-circulating parts in the decimal part. The first few digits of the denominator are 9 and the last few digits are 0. The number of 9 is the same as the number of cyclic parts, and the number of 0 is the same as the number of acyclic parts.
Baidu encyclopedia-infinite decimal
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