The purpose of this article is to present and discuss two recommended sequences of learning the areas of polygons, starting from the area of a rectangle. Exploring the algebraic derivations of the two sequences reveals that both are valid teaching progressions for introducing the area formula for various polygons. Further, it is suggested that…

Using the correct materials and manipulatives appropriately allows the richness of geometrical concepts to be fully investigated to enable students to explore and reason about shapes. This article explores some of the key ideas involved in learning about two dimensional shapes and discusses how materials can be used to support learning.

The importance of mathematical reasoning is unquestioned and providing opportunities for students to become involved in mathematical reasoning is paramount. The open-ended tasks presented incorporate mathematical content explored through the contexts of problem solving and reasoning. This article presents a number of simple tasks that may be…

The topics of decimals and polygons were taught to two classes by using challenging tasks, rather than the more conventional textbook approach. Students were given a pre-test and a post-test. A comparison between the two classes on the pre- and post-test was made. Prior to teaching through challenging tasks, students were surveyed about their…

Presents a framework for differentiating between five levels of extension of knowledge: basic features, forms, rules, application, and elaboration. Comparison of the extent of knowledge use exhibited by (n=14) Year-11 Australian students on a range of plane geometry problems found that high-achieving students exhibited greater extension of…

A series of spatial tasks involving conceptualization and manipulation of unfamiliar plane shapes administered to (n=20) children aged 4 to 12 revealed that both initial perception of a shape and approach to task solution strongly influenced children's success at shape recognition. (20 references) (Author/MKR)

Written descriptions by students in grades 3-7 (n=274) of common 2-dimensional geometric shapes were examined to compare the level descriptors of the van Hiele Theory and the SOLO Taxonomy. Results indicate that descriptors associated with the SOLO Taxonomy more accurately describe the quality of student thinking. (MDH)