  These few pages briefly present the way in which Activity Theory has been
adopted for several years now by French researchers in didactics of mathematics
and has been adapted to study the learning of school mathematics in relation
with the teaching that students receive, as well as teachers practices. Common
general features of the methodology that each one afterwards worked on and
continues to develop according to his own research objects, make it possible to
specify some principles deriving from well-known learningTheories. Some results
are outlined, as well as difficulties and perspectives.
