Here is an example of the Picaxe chip driving a single common anode seven segment display.
Your task is to write some code to make the display count from 0 to 9 repeatedly.

Multiplexing

Several displays can be used very easily by multiplexing. Output 7 and the eight digital inputs (used as outputs) can be used to select which of the displays is active. An emitter follower circuit can be used to power the correct display. Output pins 0 to 6 control which segments are lit. Diodes are used to ensure the power flows only to the correct display.

 

This diagram shows how to multiplex two displays. Adding more displays simply requires the same circuit again (yellow highlight). In this example, each display is on for 50% of the time (maybe less depending how well you write your code). This will make the displays less bright. Once the code is debugged and not going to be changed again, the series resistors can be reduced to restore full brightness. in this case, you need double the current for 50% of the time so 150 ohms might be suitable.

IMPORTANT: This technique runs into problems because the picaxe chip can not provide enough current to drive the LEDs. In this case, buffer circuits or chips are needed.

' CODE SNIPPET
    b1 = %01011111
start:
    low portc 0
    pins = b1
    pause 500
    high portc 0
    pins = b1
    pause 500
    low portc 1
    pins = b1
    pause 500
    high portc 1
    pins = b1
    pause 500
    goto start