pdexpand returns the periodic decimal expansion of the given rational number n.

Every rational number has a periodic (or terminating) decimal expansion. The converse is also true; a periodic expansion always represents a rational number.

The result is returned as in the form  where s is the sign of n, q the positive integer part, np the non-periodic part, and p the periodic part of n.

Use convert/rational to find the rational number of a periodic decimal expansion.

The command with(numtheory,pdexpand) allows the use of the abbreviated form of this command.