@KLAUS at no point was floating point mentioned - Akanimo mentions ufixed with the a VHDL fixed point representation type. It is a type that does fixed point mathematics in a convenient type. It is simply integer arithmatics as suggested.
Using integer maths (like signed/unsigned) requires the user to track the integer fraction separations in words. With fixed point types, this is all handled for you in the type and no bit selection needed.
@Akanimo
To display on a screen, you'll need some form of display driver. Or are you simply trying to display the value on a console during simulation?