This study suggests that the implementation of non-decimal numeration as a vehicle of instruction seems to have no effect on mathematical understanding of base 10. (Author/CP)

Reported is a study which measured conservation of length among kindergarten and first-grade subjects using several verbal and nonverbal procedures. The results indicated that conservation of length is not a simple unitary concept, but has empirical gradations. (Author/CT)

Discussed is the meaning and misuse of the concept of relation" in mathematics textbooks. The logical meaning of relations upon which set theory meanings are superposed is explored. (JG)

The author suggests that a close analysis of existing calculus courses indicates that some of the material can be explained much more clearly by using some of the language of set theory. He gives examples showing that many of the pedagogical problems arising in calculus can be overcome by using a graphical approach. (FL)