pcf8574p port expander addressing

Can anyone elaborate on the addressing of this chip? With A0, A1, and A2 connected to ground the address is

#define expander B00100000

How do i go about changing the address? What is the alternate to connecting the addressing pins to ground and how would that correlate with the #define statement?

It's in the data sheet for more detail. But the last 000 ( B00100(000) are corresponding to pins A0,A1,A2 of the chip itself. Your two options are gnd or V+. So for example: If you put A0 and A1 to V+ and A2 to Gnd the address would be =

B00100110

Thank you for the clarification.