The problem of placing stamps on a grid is presented, with variable forms of the problem and various levels of the solution described. (MNS)

The Euclidean algorithm for finding the greatest common divisor is presented. (MNS)

Results demonstrate that number can be abstracted from an array of elements in estimating. Estimation appears to be based on the perception of a higher order structure, and persons of 8 years and older are able to abstract the structure from an array of objects. Even 6-year-old children can be trained to estimate by abstracting number. (Author/RH)

Problems which can be solved or partially solved by the Gregory Interpolation Formula are presented. The formula is explained and applied to three problems. (MNS)

An attempt is made to detail the nature of mathematics as perceived by mathematicians. Mathematics is viewed here as both abstract and an experimental science. The typical working mathematician is described as proceeding through problems with an attitude of discovery and examples of such an approach are given. (MP)

Two traditional presentations introducing the calculus of exponential functions are first presented. Then the suggested direct presentation using calculators is described. (MNS)

A choice reaction time experiment tested the idea that the operations performed on symbols from different notational systems depend, not only on the interpretation of the symbols, but also on the symbol's notational characteristics or the ways in which they map the world. (Author)

A human interest account of the discovery of a mathematical formula is given. (Author/MK)

Describes a program written in BASIC, called BIGNUM, that was designed to aid in handling big numbers. The program adds, subtracts, multiplies, divides, and raises to a power integers of up to 1024 decimal digits and is thought to be usable on many types of machines. (MP)

In a replication study, children 3 and 4 years old were given verbal rule training in order to probe the importance of identity, reversibility, and compensation explanations in training number and length concepts. Among the results, as before, identity was found to be the most significant factor in conservation acquisition. (Author/RH)

Results at the end of one year showed that the experimental group mastered an average of 32 objectives while the control group averaged 15.5, suggesting that hierarchically sequenced mathematics curricula may provide an effective approach to the teaching of number concepts to the severely and moderately retarded. (Author/DLS)

Small graphic changes made in normal letters of the alphabet changed the similarity relations among those letters. Children and adults classified letters of this distinctive font faster and with fewer errors than they did normal letters. Relations between letters in the stimulus set determined how difficult any particular letter was to classify.…

Common mistakes pupils make when adding fractions are categorized and analyzed. (MP)

The article presents a general test for divisibility that includes composite numbers and shows that such a test can be used to determine divisibility by several numbers simultaneously. (MK)

Suggestions for teaching the concept of division by zero are given. (MK)