James wrote:

"If that is the case why is it I always get a result of maximum of 3
decimal palces only"

Where do you execute your query from? If you execute it from one of the
popular db manager tools (IBE, IBManager, etc.), then there is a
floating display format setting defaults to ",##0.000" format, that is
formats every float number to 3 digits precision (in the result dbgrid).

Regards: Alex