An information retrieval system which aspires to retrieval of relevant documents should have second stage which will order topical set to provide maximum informativeness to requestor. A two-stage system concerned only with topicality can be iterated to generate a high recall set and discard imprecise documents without user input. (EJS)

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

This review of four different computer-assisted instruction algorithms concludes that current authoring guides are more concerned with "user orientation" than with instructional principles, and advocates the application of a design model based on Gagne's information processing model of instruction. Nine references are listed. (MER)

A traditional question is whether or not computers shall ever think like humans. This question is redirected to a discussion of whether computers shall ever be truly creative. Creativity is defined and a program is described that is designed to complete creatively a series problem in mathematics. (MP)

A history of perfect numbers is presented, which briefly covers the 27 values known at this time. (MP)

Two alternatives are given to the decomposition and equal addition subtraction algorithms. (MK)

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

There are many uses for the shortest path algorithm presented which are limited only by our ability to recognize when a problem may be converted into the shortest path in a graph representation. (Author/TG)

Proposes a programing design curriculum based on three conceptual areas: process, symbolic representation, and methods of interpretation; and describes computer games and simulations in which design skills of simple and conditional sequencing, rule or constraint specification, hypothesis testing, and modeling are employed. (Author/CMV)

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)

An algorithm for multiplying natural numbers is described. The algorithm provides a chance for some unusual drill and might serve as an enrichment topic. (MK)

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

Four different types of problems from graph theory are presented and discussed. (MK)

Suggestions are given for teaching flowcharting at the elementary school level. A short list of sources for free materials on computers is included. (DT)

Reviews the historical development of subtraction algorithms used in the United States. Indicates that the algorithms used to teach subtraction have not changed much in the last 40 years, but in the late 1800s and early 1900s, different algorithms were developed that had a great impact. Contains 22 references. (DDR)