Single digit Light Emitting Diode (LED) modules for replacing plastic numerals in a gas station pricing sign. Three or four LED modules represent one fuel price. The LED modules are mounted to a transparent face present on existing signs, and may be mounted on an exterior or interior surface of the face. In one embodiment, first LED modules mechanically cooperate with backing plates, thereby sandwiching the face, in another embodiment, second LED modules attach to posts glued to the face. When mounted externally, the LED modules fit into tracks provided for the plastic numerals which are being replaced. An RF, infrared, or hard wired control signal may be used to change prices, and a photocell may be used to control LED intensity in response to ambient light. Additional low power consumption LEDs are provided inside the sign to back illuminate information provided on the face.