The article surveys the practices in residential schools for the blind concerning the use of computational devices and the types of teacher training in the use of the abacus. Consensus of facts and opinions voiced by respondents from 30 residential schools is reported. The major emphasis is on the effective use of the abacus. (Author/SBH)

Early calculating methods and devices are discussed. These include finger products, the abacus, ancient multiplication algorithms, Napier's bones, and monograms. (MP)

The use of the programmable calculator is discussed for obtaining numerical solutions to equations. The program is listed and the method illustrated. (MP)

Two experiments investigated extent to which English- and German-speaking childrens' mental arithmetic was constrained by working memory. Found higher mental addition spans when numbers were visible throughout calculation than when not. Variation in addition span with age and arithmetical operation difficulty approximated to a linear function of…

Provides an alternative to traditional instruction in multiplication and division to develop computational fluency in students. (Author/NB)

Discusses the importance of developing teachers' computational fluency so that they can effectively support their students' fluency work. Provides suggestions for helping teachers develop computational fluency with subtraction. (Author/NB)

Discusses classroom practices that promote the understanding of number concepts in the primary grades. (Author/NB)

Explains "Mathematical Mind Journeys," a lesson format that promotes computational fluency through variable practice that relies on mathematical memory rather than rote memorization. (Author/NB)

Presents math games with die designed to help students learn addition, subtraction, and multiplication while having fun. (KHR)

Results supported the proposition that children's early counting has important limitations and strengths. Subjects, numbering 20 each at three and four years of age, differentiated appropriately between how-many and compare-sets counting tasks while using basically undifferentiated strategies. This suggests that correct judgment processes…

The differences between measuring light intensity for the human eye and for plant photosynthesis are discussed. Conversion factors needed to convert various units of light are provided. Photosynthetic efficiency and the electricity costs for plants to undergo photosynthesis using interior lighting are described. (KR)

Discusses the theory of collaboration and measures of collaboration. Variables for collaborative measures are considered, principles are formulated that good collaborative measures should satisfy, examples and practical calculations are presented, and further problems for research are suggested. (nine references) (LRW)

Reports on the performance of a demented elderly patient who, although he had impaired functions in several cognitive domains, showed exceptional calculating abilities superior to those of young adults. Addresses the problem of various mathematical dissociations at different levels. (Contains 30 references.) (Author/ASK)

Rough set theory is a new mathematical tool to deal with vagueness and uncertainty. Computational methods are presented for using rough sets to identify classes in datasets, finding dependencies in relations, and discovering rules which are hidden in databases. The methods are illustrated with a running example from a database of car test results.…

Develops and analyzes four algorithms for feature selection in the context of rough set methodology. Experimental results confirm the expected relationship between the time complexity of these algorithms and the classification accuracy of the resulting upper classifiers. When compared, results of upper classifiers perform better than lower…