Building a calculation string

Hiya folks,
I'm trying to build up a calculation string the values and operators will (eventually) be held in a SQL table. But for now i'm just testing it using the query analyzer. Please see example code below:

Declare @.MyFirstNo varchar(50)
Declare @.MySecondNo varchar(50)
Declare @.MyStringPart varchar(50)
Declare @.MyCalcString varchar(50)
Declare @.MyResult varchar(50)

SET @.MyCalcString = ''
SET @.MyFirstNo = 10
SET @.MySecondNo = 3
SET @.MyStringPart = '/'

SET @.MyCalcString = @.MyCalcString + @.MyFirstNo
SET @.MyCalcString = @.MyCalcString + @.MyStringPart
SET @.MyCalcString = @.MyCalcString + @.MySecondNo

create table #tmp1(result decimal(18,5))
insert #tmp1
exec('select '+@.Mycalcstring)
select @.MyResult = result from #tmp1
drop table #tmp1

Print @.MyResult

So the calculation is : 10/3. Which results in an answer of 3.00000. Which is obviously wrong. If I declare the variables as 'decimal' then I can't build the calcation string, with an error of 'Error converting varchar to numeric'.

Any offers?

Love and peaceDeclare @.MyFirstNo varchar(50)
Declare @.MySecondNo varchar(50)
Declare @.MyStringPart varchar(50)
Declare @.MyCalcString varchar(50)
Declare @.MyResult varchar(50)

SET @.MyCalcString = ''
SET @.MyFirstNo = 10.0
SET @.MySecondNo = 3.0
SET @.MyStringPart = '/'

SET @.MyCalcString = @.MyCalcString + @.MyFirstNo
SET @.MyCalcString = @.MyCalcString + @.MyStringPart
SET @.MyCalcString = @.MyCalcString + @.MySecondNo

create table #tmp1(result decimal(18,5))
insert #tmp1
exec('select '+@.Mycalcstring)
select @.MyResult = result from #tmp1
drop table #tmp1

Print @.MyResult|||Thanks for taking the time to reply, (although it took me a while to spot what you'd changed!!!). Seems to have done the trick, now comes the extensive testing! Any problems and I'll let you know.

Love and peace