When you write a number such as 7.9467, it is a way of representing it. When the numbers are rational, there is no problem, this way of writting numbers is unique, however, when you try to write numbers that are real, this representation is sometimes problematic, since two different writting can represent the same number. In particular, when you write 0.99999... (where ... neans an infinite number of 9's), this represents the same number as writting 1, since according to the decimal notation, 0.9999.... represents the limit of the series sum of 9/10<sup>n</sup> with n = 1 to infinity. the limit of this series is indeed equal to 1.