A classification of the simple combinatorial configurations which correspond to various cases of distribution and ordering of objects into boxes is given (in French). Concrete descriptions, structured relations, translations, and formalizations are discussed. (MNS)

It is suggested that elementary school students find rational numbers troublesome because some teachers have an inadequate understanding of rational number concepts and poor facility with rational numbers skills. How to help them overcome difficulties, develop concepts, and know what topics to emphasize are discussed. (MNS)