A curious string of nines
Hans Liebeck · The Mathematical Gazette · 2001
The well-known non-terminating decimal expansion has the property that, if the first half of the recurring part, 142, is added to the second, 857, the result is 999. Surprisingly, this is not a ‘one-off’ phenomenon. For example,The reader is invited to test and . Further examples will be found in John R. Silvester’s article. We shall examine when and why the above property of recurring decimals occurs.