Decimal numbers are based on powers of 10. The only factors of 10 are 2 and 5. Any denominator of the form 2^x*5^y will divide 10^x or 10^y - whichever is larger.
In the above example, the first set of denominators are all of the form 2^x and so will divide 10^x. So all fractions will have decimal expressions with x decimal digits (assuming you start with the fraction in simplified form).
The second set of denominators include 3 as a factor and so none of these denominators can be expressed as 2^x*5^y and so none of them are a factor of 10^z for any z.
All that may sound complicated. At its simplest, the rule is that if the only prime factors of the denominator are 2 and 5, then you will get a terminating decimal. Anything else and you won't.
No, no repeating decimal is irrational. All repeating decimals can be converted to fractions. They are, however, non-terminating.
irrational numbers
A terminating decimal reaches an end after a finite number of digits whereas a repeating decimal, after a finite number of digits, has a string of decimals (also of finite length) that repeats forever. Thus 1.2356 is a terminating decimal. 1.456333... is a repeating decimal with the digit 3 repeating an infinite number of times. So also is 23.56142857142857...... where the string 142857 repeats to infinity. In fact, terminating decimals may be viewed as repeating decimals with zero repeating infinitely.
There are times when working with fractions is more convenient than working with decimals.
A rational number is any number that can be expressed as the quotient or fraction p/q of two integers, p and q, with the denominator q not equal to zero. Terminating or repeating decimals are the result of this.
No, no repeating decimal is irrational. All repeating decimals can be converted to fractions. They are, however, non-terminating.
fractions or decimals
terminating decimals repeating decimals
terminating decimals non terminating decimals repeating decimals non repeating decimals
Terminating and repeating decimals are rational numbers.
They are called rational numbers
Fractions are related to repeating decimals in the sense that a fraction can be represented as a repeating decimal if the denominator has prime factors other than 2 or 5. For example, 1/3 can be represented as 0.3333..., with the 3s repeating infinitely. Terminating decimals, on the other hand, are fractions that have denominators which are powers of 10. For example, 1/4 can be represented as 0.25, which terminates after two decimal places.
All terminating decimals can be written as fractions.
terminating decimals and repeating decimals
Terminating and repeating decimals are.
No.
They are called terminating decimals.