Period of Reciprocal of 729 is 81/Mistake

Source Work

 * The Dictionary
 * $729$
 * $729$

Mistake

 * ''$1 / 179$ has a decimal period of $81$ digits, which can be arranged in groups of $9$ digits, reading across each row, in this pattern:

The red digit is wrong. Instead of $6$ it should be $0$: