This paper describes the conceptions about complex numbers that a group of university students has, these were built from the application of an activity sequence centered on these numbers. This sequence is based on the APOS theory, some aspects of semiotic representation theory, and the use of digital technology. Particularly, both the general…

The study compared two methods of teaching an initial place value skill: a concrete, semiconcrete, abstract teaching sequence and an abstract-only presentation. Learning-disabled elementary and middle school students (N=24) using the concrete to abstract teaching sequence performed significantly better on three posttests than students taught the…

The fraction concept was analyzed to yield 16 subconcepts which are hypothesized to be hierarchically ordered. This ordering was tested using subjects in grades 4 through 6, and 18 of 23 dependencies hypothesized were confirmed. (SD)

Instructions for using and constructing approximately 58 instructional materials to aid young visually handicapped children in developing basic sensory concepts are presented. The materials are said to foster important ideas in variously aged children who have difficulty using their hands or understanding numerical concepts. Use of the materials…

This article presents the "concrete semiconcrete abstract" (CSA) teaching sequence for teaching basic math skills to students with and without learning disabilities. Guidelines include providing a minimum of nine instructional lessons (three at each level), each with four lesson steps. Validation of the CSA sequence and lesson format with 15…