There are 2 numbering systems for the GPIO pins. The one used on the Sparkfun wedge are the "BCM" numbers. Those relate to the pins on the processor chip.
The numbering used for the relay board plugins are the "board" (physical) numbers. You can see a cross reference of both number systems at:
https://pinout.xyz/#
The board numbers are the small numbers close to the pins in the diagram. The reason for using board numbering is that it remains constant across Pi models. You can click on a pin number on the diagram to get a full cross reference and description of the pin.
The numbering used for the relay board plugins are the "board" (physical) numbers. You can see a cross reference of both number systems at:
https://pinout.xyz/#
The board numbers are the small numbers close to the pins in the diagram. The reason for using board numbering is that it remains constant across Pi models. You can click on a pin number on the diagram to get a full cross reference and description of the pin.