If you divide two ints you get and int back.
Declare @P float
Declare @U float
set @P = 1
set @U = 33
Print @P / @U
or to force the int's to a float
Declare @P int
Declare @U smallint
set @P = 1
set @U = 33
Print 1.0 * @P / @U
Ie, add a float to the formula