In my worksheet, I have a regular price for general customers and then
another for the bigger buyers. How do I not round off in my formula?

Example:
=A1-10%-5%-5%
OR
=1.1-10%-5%-5% should equal .89 not .90 which I am getting.

I have to do it this way because I can't just take off 20%(i get a totally
differnet #). Please help!!