The study evaluated an errorless procedure for teaching nine educable mentally retarded students to solve missing minuend problems. Seven Ss acquired the target skill in a nearly errorless fashion in 75 to 172 minutes of individual training time. The other Ss required programatic alterations. (Author/CL)

Discoveries of Charles Babbage in the 1800s are described. Origins of the difference engine, his calculating machine, the principles of computation applied to tables, and the design and construction of his engine are included. (MNS)

A study involving dyslexic children (10-14 years old) with average and high reasoning ability and nondyslexic children with and without superior mathematical ability suggested that the high reasoning dyslexic Ss had similar abstract reasoning ability but lower computation and memory skills than mathematically gifted nondyslexic Ss. (CL)

Examines some of the issues that underlie the conceptual structure of the computational approach to cognition. Finds that this approach construes symbolization too narrowly, thereby blocking more adequate treatments of learning and acquisition of skills. Discusses the notion of symbol and symbolization and suggests an alternative approach to the…

The article suggests possible reasons for difficulties with verbal (word) problems and describes two remediation strategies: re-teaching the introductory sequence for an operation and having students write their own problems. (CL)

The potential uses for Chisanbop, a Korean system of using fingers for calculating, in the education of the elementary grade visually impaired student are explored. (Author/SBH)

Tips are presented for chemistry teachers on the use of acid-base half-reactions in review lessons, the use of calculators by chemistry students, significant figures, and the preparation of benzoyl peroxide from acne medicine. (BB)

Focused on cardinality acquisition (thought to be crucial to correct counting) and on the relation between cardinality and counting. Gathered data with three groups of children three to five years old on four kinds of tasks. Found no empirical evidence for considering counting as a single prerequisite to cardinality. Suggests new approach to…

Proposed three criteria to distinguish calendrical savants whose skills depend on memory from those who calculate and applied these to 10 calendrical savants. Results are discussed in relation to views that calendrical savants imply the existence of a modular mathematical intelligence or unconscious integer arithmetic. (SLD)