The "Forty Electronic Challenges" is a "discovery learning" and socio-constructivist science activity that has become rather popular in Canada. The article recalls its emergence and development. It discusses its theoretical underpinnings and how it fits into the existing literature. It then gives educators all the guidelines they need to use it autonomously, and presents observations derived from our extensive use of the activity over the years. Finally, a discussion of its promises, limitations, and possible extensions is presented.