When a number
can be written as a decimal with only a finite number of places,
it is called a terminating decimal. For example,

3/5 = 0.6 7/8 = 0.875
and 17/625 = 0.0272

Such decimals when expressed as fractions always have denominators
which consist of power of 2 and/or a power of 5. In contrast,
the decimal forms of irrational numbers such as √2
and π do
not terminate. A recurring decimal such as 0.428571428571428571428571...,
which is equal to the fraction 3/7 also does not terminate.