Definition:Recurring Decimal

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Definition

A recurring decimal is a non-terminating decimal whose decimal expansion ends with a finite number of digits which repeats itself ad infinitum.


Examples

Example: $0 \cdotp 333 \ldots$

The number $\dfrac 1 3$ can be expressed as a terminating decimal:

\(\ds \dfrac 1 3\) \(=\) \(\ds 0 \cdotp 333 \ldots\)
\(\ds \) \(=\) \(\ds 0 \cdotp \dot 3\) using recurrence notation

This would be voiced:

nought point three recurring

or:

zero point three recurring

and so on.


Example: $0 \cdotp 714 \, 285 \, 714 \ldots$

The number $\dfrac 5 7$ can be expressed as a terminating decimal:

\(\ds \dfrac 5 7\) \(=\) \(\ds 0 \cdotp 714 \, 285 \, 714 \ldots\)
\(\ds \) \(=\) \(\ds 0 \cdotp \dot 714 \, 28 \dot 5\) using recurrence notation


Also known as

A recurring decimal is also known as:

a repeating decimal
a periodic decimal.


Also see

  • Results about recurring decimals can be found here.


Sources