# Period of a Rational Number

## Period of a Rational Number

When writing a rational number in decimal notation, a group of digits that repeats in the decimal part of the number.

### Symbol

In the decimal notation of a rational number, the notation of the period p consists of drawing a line over the sequence of numbers that repeats.

In the decimal notation of the rational number $$\dfrac {22} {7}$$ = 3.142 857 142 857 14 …, the period is 142 857.
$$\dfrac {22} {7} = 3.\overline {142\space857}$$ and we write: p = 142 857.

### Examples

• $$\dfrac{5}{3}$$ = 1.666 666 666 … = 1.$$\overline {6}$$ and we write: p = 6.
• If the rational number is one decimal number, the period is 0.
$$\dfrac{7}{5}$$ = 1.4 and we write: p = 0.