Calculations for a field in template

Hello , 

If i have rtf template , in it there is a field  :

(SalesLeaseFactorRFG)?>

But the issue is that the field is coming in the xml file like : 

<SalesLeaseFactorRFG>.085948</SalesLeaseFactorRFG>

So in the rtf i want it to be shown like :

85.948

So i am trying : 

(SalesLeaseFactorRFG*1000)?>  'REGULAR TEXT' or 'Number'

or:

<?(SalesLeaseFactorRFG*10)*100?> 'Number'

The issue is that the calculations for the first is working fine for me , but for the customer it is not stable , i mean the value changes , some 

times 85.94800000000001

So i need to know the standard syntax , while my requirements is to multiply the number with 1000 in order to have it in the proper format that i need .