The relative error in VB

Hi all, I have a problem using floating-point operations (division,multiplication,addition,subtraction)
Еxpressions like 2/3 or 1/3 or others can not be calculated exactly, this is a serious problem for me now! My question is if there is somewhere suitable software or some way that I can use to define an interval of admissible error
Is it possible to find a software that calculates that interval of admissible error every time when i make a computation.
Thanks!!!

I think this article on Wiki will be of intrest to you.
The links in the Conversion and Rounding Paragraph in particular.

http://en.wikipedia.org/wiki/Floatin...n_and_rounding

Thanks!
But let me to ask again if there is a software which calculates an interval of admissible error every time when a computation is done :)