What factors greatly affect fps(frame per sec)?

Hi all,

In old computer (Apple 6502), multiplcation and division takes more time to process than addition and subtraction.

Are there any advantages using :
1. "Shift left/right" command,
2. lookup table technique
to by passby multiplcation and division?

Or Blitz3D already can multiply and divide very fast and there is no need to do this?

Thanks in advance.
Sammy
:)