Young children reasoning about symmetry in a dynamic geometry environment

Geometry in the early years: a commentary

“…Use of dimensional deconstruction tasks that involve the physical, graphical and geometrical spaces in problem solving Ng and Sinclair (2015) Canada Grade 1/2 and grade 2/3 split class Part of a year-long teaching experiment with children from grades 1 to 3 on symmetry using Sketchpad as well as paper-and-pencil environments Thom and McGarvey (2015) Canada Grades 1 and 2…”

“…Several of the papers in this issue have reported the use of technology. For example, Ng and Sinclair (2015, this issue) used the Sketchpad in their research on symmetry. Kostopolous, Cordy and Langemeyer (2015, this issue) report the use of iPads in their research whereas Kaur reports the use of interactive whiteboards.…”

“…There are nine papers based on empirical research from both sides of the Atlantic that involve young children. These nine papers cover various aspects of geometry and/or spatial reasoning (see Table 1): symmetry (Ng and Sinclair 2015), drawings (2015) Italy…”

Recent research on geometry education: an ICME-13 survey team report

“…Using this theoretical framing, Kaur shows how young children "developed a reified discourse on triangles, which involves inclusive descriptions of classes of triangles (in other words, they thought about equilateral triangles as special types of isosceles triangles)" (ibid p. 407). Ng and Sinclair (2015a) investigated young children's learning of reflectional symmetry. Ng and Sinclair (2015b) investigated 13-14 year old students' learning of area through a geometric approach, using shearing.…”

“…2a). Ng and Sinclair (2015a) show how grades 2/3 children use gestures to communicate central ideas about reflectional symmetry, such as the equidistance from the line of symmetry (see Fig. 2b).…”