The operation of rounding is shown to lead into an investigation of an abstract mathematical system. Properties of the system are discussed and graphs of the rounding function are drawn. Some questions for discussion are given. (MP)

The topics discussed are, "Helping Students Understand the Distributive Property,""Converting from Base 10: Nonintegral Bases?,""Rapid Mental Squaring of Mixed Numbers," and "Some Nonstandard Binary Operations and their Properties." (JT)

Worksheets for the lower grades involve locating numbers on the number line; the activities for the upper levels focus on the estimation of sums and products. (DT)

A theorem on divisibility in decimal and non-decimal numeration systems is developed; its use in a series of discovery-centered lessons is suggested. (DT)

Presents techniques and materials for instruction at secondary school and upper elementary grades in mathematical concepts of number systems structure. Grouping is used as a simple algebraic system to illustrate structure. Closure, inverse, identity, commutative and associative properties are examines relative to manipulation of geometric figureS.…

Arguments given against switching to the metric system include: the metric system is foreign; only scientists need the metric system; and who needs systems of measurement, anyway? (MP)

Analyzed construction of approximative expressions with two numerals in Dutch. Found that choice of number words was not arbitrary and that various kinds of factors are involved. Results suggest that analogue magnitude code is used in estimating and comparing, and human cognition seems to be able to perform simple calculations with quantities,…

Presents evidence that human infants possess a mechanism for determining and representing small numbers of entities and procedures for operating on these representations to extract numerical relationships between them. Presents a model for this mechanism and discusses its relation to later numerical knowledge. Contains 42 references. (MKR)

In this article, the author believes that a visual image of the number system is helpful to everyone, especially children, in understanding what is, after all, an abstract idea. The simplest model is the number line, a row of equally spaced numbers, starting at zero. This illustrates the continuous progression of the natural numbers, moving to the…

An attempt to introduce subtraction of negative integers early in the secondary school curriculum is described. The attempt was not successful, and several aspects of the experiment are discussed. (SD)