You can format the cell as (menu Format > Cell, tab Number):
Category: Custom
for Type, enter: # ??/32
This will ensure the fraction stays in 32th.
However, now, if you enter 2/64, it will be reduced to 1/32. And i don't
think you can prevent the reduction, besides formatting the cell as Text, but
in that case the value looses its mathematical significance and when trying
to convert it back using =VALUE(A1) it may be understood as a date instead.
Regards,
Sebastien
