The present study is a part of design research in local instructional theory in a pre-algebraic lesson using the Realistic Mathematics Education (RME) approach. The article will focus on recommendations for the type of pre-algebra class that supports elementary school students' algebraic thinking. As design research study, it followed the three…

This unit describes an experience in informal geometry that is based on work with construction paper and milk cartons. The description is mostly of work actually carried out by children in the elementary grades involving such mathematical concepts as congruence, symmetry, the idea of a geometric transformation, and some basic notions of elementary…

A unit on the peoperties of a kite can include many geometric concepts: symmetry, distance, relationships between diagonals, area, altitude, angles, and others. (SD)

Having students find and cut out of graph paper the 12 pentominoes can provide an enjoyable exercise in perception, discovery, and double checking. The pentominoes can then be used to illustrate informally several geometric concepts. (SD)

When primary children were interviewed to determine their perceptions of embedded triangles, they failed to observe overlapping triangles. Possible explanations for this and other response patterns are discussed, and implications for schooling are explored. (SD)

A series of lessons in which the concept of symmetry is informally developed is described. Rotational and reflection symmetries are examined. Pictures and sample worksheets illustrate the article. (SD)

A learning activity relating modular arithmetic to patterns of figures determined by points equally spaced around a circle is described. (SD)

Helping students notice the geometric shapes and symbols around them and in the world's cultures is a fascinating way to make mathematics meaningful. (Editor/SJL)

Activities in which students make models of a variety of geometric solids are described. (SD)

Beginning with a set of design cards and a rectangular grid, students can generate interesting and colorful designs using rotations, reflections, and translations. (SD)

While repairing a sleeping bag, the author observed that the quilt stitching was unicursal. This led to development of a classroom activity relating the stitching patterns of quilts to the highest common factor of the numbers of "bumps" in each direction. (SD)

Paper squares, each divided into eight congruent triangles, can be used in a variety of activities introducing ideas related to symmetry, pattern, and geometric transformations. (SD)

A series of activities involving figurate numbers that allow students at various levels to integrate numerical, geometric, arithmetic, patterning, measuring, and problem-solving skills are presented. A discussion of the geometric and numerical aspects of figurate numbers is included. Appended are IBM Logo procedures that will create pentagonal…