Shapes recognition in early school: How to develop the dimensional deconstruction?

International audienceIn primary school there is, in geometry, an important rupture between primary (age 4 to 12) and secondary school. Some activities are already proposed for students from 8 to 12 years old to help to prepare for this rupture. Our research has the same aims, but for students from 4 to 6 years old by developing some pre-geometrical activities around shape recognition using dimensional deconstruction