Sparkfun Electronics Inventor's Kit Manual page 48

How do you know which pins are paired up? The buttons included in this kit will only fit across the
breadboard ditch in one direction. Once you get the button pressed firmly into the breadboard
(across the ditch), the pins are horizontally paired. The pins toward the top of the breadboard are
connected, and the pins toward the button of the breadboard are connected.
Note: Not all buttons share this pin format. Please refer to the datasheet of your specific button to
determine which pins are paired up.
Hardware Hookup
Ready to start hooking everything up? Check out the wiring diagram and hookup table below to see
how everything is connected.
Polarized Pay special attention to the component's markings indicating how to place it on
Components the breadboard. Polarized components can only be connected to a circuit in one
direction.