Get Numbers In Front Of Street.

After reading performance tuning articles and stuffs. Im getting confussed about writing my queries. One point says don't use 'not in' instead use 'not exists'. But looks i cant implement that in my query.

I'm trying to get only the decimal numbers. not the fractions.
my question is if this is the best query? Inputs will be appreaciated.




declare @table table (tableid int identity, ad_str1 varchar(100))
insert @table
select '2 NORTHPORT AVENUE' union all
select '22 NORTHPORT AVENUE' union all
select '233 NORTHPORT AVENUE' union all
select '2433 NORTHPORT AVENUE' union all
select '2 1/2 NORTHPORT AVENUE' union all
select '22 1/3 NORTHPORT AVENUE' union all
select '233 1/4 NORTHPORT AVENUE' union all
select '2433 1/8 NORTHPORT AVENUE' union all
select '2a NORTHPORT AVENUE' union all
select '22a NORTHPORT AVENUE' union all
select '233a NORTHPORT AVENUE' union all
select '2433a NORTHPORT AVENUE' union all
select '2 a NORTHPORT AVENUE' union all
select '22 a NORTHPORT AVENUE' union all
select '233 a NORTHPORT AVENUE' union all
select '2433 a NORTHPORT AVENUE' union all
select 'a NORTHPORT AVENUE' union all
select '15 e NORTHPORT AVENUE' union all
select '15 n NORTHPORT AVENUE' union all
select '15 s NORTHPORT AVENUE' union all
select '15 w NORTHPORT AVENUE' union all
select '15 c & k north avenue' union all
select '1/3 NORTHPORT AVENUE' union all
select '93 H ROAD'


select tableid, ad_str1, left(ad_str1, charindex(' ', ad_str1))
from @table
where left(ad_str1, charindex(' ', ad_str1)) not in ('1/2','1/3','1/4','1/8','2/3','3/4')
and isnumeric (left(ad_str1, charindex(' ', ad_str1))) = 1