In literary braille, the abbreviation does not have to stay on the same line as the number assoicated with it. However, in Nemeth, the abbreviation cannot be separated from the number -- both must remain on the same line. See pg 206 of the Nemeth Braille Code for Math and Science Notation, §195.c. "An abbreviation must not be placed on a different braille line from its preceding or following numeral or letter." I believe that if the [u]word[/u] four is used (rather than the [u]number[/u] 4), this rule no longer applies, since it is a word, rather than a letter, to which the abbreviation is associated.
(I assume that you meant a line break, but if it cannot be broken between lines, it cannot be broken between pages.)