Proper use of the vinculum to indicate repeating decimal.

A nerdy debate with a colleague leads me to ask this question:

To be used correctly, does the vinculum HAVE to only be placed over the shortest sequence of digits that repeat after a decimal?

For example, to indicate 1/3, is it ok to write $0.\overline{33}$ instead of $0.\overline{3}$?

Thank you!

• Does it have to be placed behind the decimal point? $\frac{100}{7} = \overline{14.2857}$? – law-of-fives May 8 '17 at 22:51
• I thought that was just a symptom of mathematicians' and math fans' preference for shorter notation regardless of its impact on clarity. – Robert Soupe May 9 '17 at 18:14

1 Answer

Yes, it is ok to write $$\frac{1}{3}=0.\overline{3}=0.\overline{33}$$

See also e.g. the related example $0.\overline{111}$ in Wolfram's MathWorld. This representation could also be used to enhance readability.