Types of Decimal Numbers
The decimal part of an exact decimal number is composed of a finite number of digits.
Repeating Decimal or Recurring Decimal
The decimal part, called the period, is repeated endlessly.
The decimal part is composed of an irregular part and a regular part, also known as a period.
Not Exact and Non-Recurrent
Given a fraction, its decimal number can be calculated by taking the denominator and decomposing it into factors.
If the denominator has a factor of only 2, or only 5, or 5 and 2; the fraction is decimal exact.
If the denominator does not have a factor of 2 or 5, the fraction is a repeating decimal of the first type.
If the denominator has factors other than 2 or 5, the fraction is a repeating decimal of the second type.