Presents the results of a review of chemistry textbooks aimed at finding values for the equilibrium acidity constant for water and the hydronium ion. Only three of 23 give correct quantitative values for water and none for hydronium. Provides calculations of the constant for both water and the hydronium ion. (JM)

Studies abacus calculation to explore the development of skills and the resulting consequences. Consideration of the effects of abacus training, transfer of the skill to other tasks, and the contexts in which abacus skill develops demonstrates the multiple ways in which specific skills can contribute to cognitive development. (ETS)

A hierarchical-clustering technique was used to examine relationships among computation-related skills by pupils in grades one to four in two Irish schools. A clear hierarchical ordering of skills was obtained at each grade. (MNS)

Presents a list of Apple software that helps students develop specific skills through supplemental learning at home. Software, including program, manufacturer, grade level(s), and price, is provided for: writing; spelling; grammar; vocabulary; reading comprehension; computational mathematics; and mathematics concepts/applications. Also provides…

Mastering the basic number combinations involves discovering, labeling, and internalizing relationships, not merely drill-based memorization. Counting procedures and thinking strategies are components, and it may be that using stored procedures, rules, or principles to quickly construct combinations is cognitively more economical than relying…

The author first corrects Baroody's description of the network retrieval model for basic number facts, in which facts are stored in memory and retrieved as needed. He then indicates weaknesses in Baroody's argument. (MNS)

Four types of computational estimation were explored in relation to other mathematical skills and sex differences with 309 eighth graders. Open-ended estimation was the most difficult, followed by estimation relative to a reference number and estimation within an order of magnitude. (MNS)

Investigates preschoolers' knowledge of counting principles by examining their ability to discriminate between features essential for correct counting and features typically present but unessential. Skill in executing the standard counting procedure was found to precede knowledge of the underlying principle. (Author/AS)

The principle of the permanence of the rules of calculation is contrasted with the concretization permanence principle. Both apply to situations where some arithmetical operation known to children for numbers of a certain kind is to be extended to include further numbers. (MNS)

Four worksheets are included, providing practice in estimation, computation, pattern recognition, and problem solving involving calculator use. (MNS)

The relationship between arithmetical concepts and solution methods is discussed. A case study illustrates the contention that some children with relatively sophisticated concepts express those concepts with primitive methods. (MNS)

Many institutional researchers will find that the microcomputer leads to greater efficiency in everything that they do, especially in the two most critical elements of their jobs: thinking and communicating. (Author/MLW)

Data on sex differences in rote-counting ability for 4722 first-grade children are presented. How different data-gathering methods and different statistical treatments of the data can yield differing results are indicated. (MNS)

A model of subtraction development and the computing difficulties and research issues suggested by the model are outlined. Demands of simultaneous processes, difficulties with informal subtraction, and the impact on the counting-up procedure are discussed. (MNS)

Discusses four ways in which subtraction is more difficult than addition: (1) verbal solutions do not always parallel object solutions; (2) methods may interfere with each other; (3) special problems exist with subtraction on the number line; and (4) subtraction has multiple situational interpretations. (MNS)