English
0·999…
20 February 2010
When many maths students encounter the expression 0·999… = 1·000…, they are a bit uneasy. It challenges their preconceived notion that each number can be represented in one and only one decimal way. One stumbling-block might be that they think of 0·999… as a large but finite string of digits—even if they accept an infinite string of nines, they may still think in terms of there being a last digit ‘at infinity’. Also, some students imagine 0·999… as more of a ‘process’ than a representation of a number. […]