Using Excel 2003

I have a cell (B3) that has a value of 0.30%. Then I have another cell
(B5) that has a value of 0.35%. I want to know the difference between the
two values, which is 0.05%. I cannot just use the formula =B5-B3 because of
the greater than symbol in B3. I was thinking of using a different cell
(let's say C3) and then create a formula for that cell to extract the
symbol and then use that cell for my difference and then hide that column.
What would be the formula to hide the symbol?

Any help would be greatly appreciated