i know that u have to do something to the 3-4 but i dont know what
Depends on the context. 3-4 is a valid date - March 4, just as 12-25
is Christmas Day.
If you want to search a numeric field for a range of values from 3 to
4 inclusive, the correct syntax is
BETWEEN 3 AND 4
Since you don't give ANY clues about what kind of field you're
searching, or what results you expect, I'm groping in the dark here a
bit...!