In this paper we present a summary of the results of our research concerning 2-player combinatorial games and its applications used to teach the know-hows of the mathematical activity via certain a-didactical research situations, called SiRCs, that transpose to the classroom the activity of an actual researcher in mathematics. We use a specific kind of combinatorial game called Nim-type games and here we only present in some detail a game called the chocolate game. Our main conclusion is that SiRCs based on Nim-type combinatorial games are effective tools to introduce a genuine (but not necessarily original) mathematical research activity to students from high school and above.